Heat-not-burn (hnb) aerosol-generating devices with capsule reuse detection

ABSTRACT

A non-combustible aerosol-generating device includes a memory storing computer-readable instructions and a controller. The controller is configured to execute the computer-readable instructions to cause the non-combustible aerosol-generating device to: apply power to a heater to preheat an aerosol-forming substrate; determine whether a preheat monitor timer has exceeded a preheat timer threshold; determine whether the aerosol-forming substrate has been previously heated based on a comparison between a first threshold power level and an applied power to the heater in response to the preheat monitor timer having not exceeded the preheat timer threshold; and determine whether the aerosol-forming substrate has been previously heated based on a comparison between a second threshold power level and the applied power to the heater in response to the preheat monitor timer having exceeded the preheat timer threshold.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a Continuation-in-Part of U.S. application Ser. No. 17/479,260, filed on Sep. 20, 2021, the entire contents of which are incorporated herein by reference.

BACKGROUND Field

The present disclosure relates to heat-not-burn (HNB) aerosol-generating devices, methods of detecting authenticity, integrity and/or reuse of capsules, and/or methods of controlling HNB aerosol-generating devices.

Description of Related Art

Some electronic devices are configured to heat a plant material to a temperature that is sufficient to release constituents of the plant material while keeping the temperature below a combustion point of the plant material so as to avoid any substantial pyrolysis of the plant material. Such devices may be referred to as aerosol-generating devices (e.g., heat-not-burn aerosol-generating devices), and the plant material heated may be tobacco. In some instances, the plant material may be introduced directly into a heating chamber of an aerosol-generating device. In other instances, the plant material may be pre-packaged in individual containers to facilitate insertion and removal from an aerosol-generating device.

SUMMARY

One or more example embodiments provide a non-combustible aerosol-generating device, comprising: a memory storing computer-readable instructions; and a controller. The controller is configured to execute the computer-readable instructions to cause the non-combustible aerosol-generating device to: apply power to a heater to preheat an aerosol-forming substrate; determine whether a preheat monitor timer has exceeded a preheat timer threshold; determine whether the aerosol-forming substrate has been previously heated based on a comparison between a first threshold power level and an applied power to the heater in response to the preheat monitor timer having not exceeded the preheat timer threshold; and determine whether the aerosol-forming substrate has been previously heated based on a comparison between a second threshold power level and the applied power to the heater in response to the preheat monitor timer having exceeded the preheat timer threshold.

According to one or more example embodiments, the non-combustible aerosol-generating device may further include a capsule including the aerosol-forming substrate and the heater.

One or more example embodiments provide a method of operating a non-combustible aerosol-generating device, the method comprising: applying power to a heater to preheat an aerosol-forming substrate; determining whether a preheat monitor timer has exceeded a preheat timer threshold; determining whether the aerosol-forming substrate has been previously heated based on a comparison between a first threshold power level and an applied power to the heater in response to the preheat monitor timer having not exceeded the preheat timer threshold; and determining whether the aerosol-forming substrate has been previously heated based on a comparison between a second threshold power level and the applied power to the heater in response to the preheat monitor timer having exceeded the preheat timer threshold.

One or more example embodiments provide a non-transitory computer-readable storage medium storing computer-readable instructions that, when executed by a controller at a non-combustible aerosol-generating device, cause the controller to perform a method of operating the non-combustible aerosol-generating device, the method comprising: applying power to a heater to preheat an aerosol-forming substrate; determining whether a preheat monitor timer has exceeded a preheat timer threshold; determining whether the aerosol-forming substrate has been previously heated based on a comparison between a first threshold power level and an applied power to the heater in response to the preheat monitor timer having not exceeded the preheat timer threshold; and determining whether the aerosol-forming substrate has been previously heated based on a comparison between a second threshold power level and the applied power to the heater in response to the preheat monitor timer having exceeded the preheat timer threshold.

The controller may be configured to execute the computer-readable instructions to cause the non-combustible aerosol-generating device to terminate application of power to the heater in response to determining that the aerosol-forming substrate has been previously heated.

The controller may be configured to execute the computer-readable instructions to cause the non-combustible aerosol-generating device to output a fault indication in response to determining that the aerosol-forming substrate has been previously heated.

The controller may be configured to execute the computer-readable instructions to cause the non-combustible aerosol-generating device to allow for aerosol generation in response to determining that the aerosol-forming substrate has not been previously heated.

One or more example embodiments provide a non-combustible aerosol-generating device, comprising: a memory storing computer-readable instructions; and a controller. The controller is configured to execute the computer-readable instructions to cause the non-combustible aerosol-generating device to: apply power to a heater to preheat an aerosol-forming substrate within a capsule; determine whether a preheat monitor timer has exceeded a preheat timer threshold; determine whether the capsule is at least one of an inauthentic or degraded capsule based on a comparison between a first threshold power level and n applied power to the heater in response to the preheat monitor timer having not exceeded the preheat timer threshold; and determine whether the capsule is at least one of an inauthentic or degraded capsule based on a comparison between a second threshold power level and the applied power to the heater in response to the preheat monitor timer having exceeded the preheat timer threshold.

The capsule may be a removable capsule including the aerosol-forming substrate and the heater.

The capsule may be a degraded capsule, and degradation of the capsule may be a result of prior heating of the aerosol-forming substrate.

The controller may be configured to execute the computer-readable instructions to cause the non-combustible aerosol-generating device to terminate application of power to the heater in response to determining that the capsule is at least one of an inauthentic or degraded capsule.

The controller may be configured to execute the computer-readable instructions to cause the non-combustible aerosol-generating device to output a fault indication in response to determining that the capsule is at least one of an inauthentic or degraded capsule.

The controller may be configured to execute the computer-readable instructions to cause the non-combustible aerosol-generating device to allow for aerosol generation in response to determining that the capsule is not at least one of an inauthentic or degraded capsule.

The first threshold power level may be less than the second threshold power level.

The applied power may be a maximum power applied to the heater or a power target for the heater.

The first threshold power level and/or the second threshold power level may be based on the maximum power or the power target.

BRIEF DESCRIPTION OF THE DRAWINGS

The various features and advantages of the non-limiting embodiments herein may become more apparent upon review of the detailed description in conjunction with the accompanying drawings. The accompanying drawings are merely provided for illustrative purposes and should not be interpreted to limit the scope of the claims. The accompanying drawings are not to be considered as drawn to scale unless explicitly noted. For purposes of clarity, various dimensions of the drawings may have been exaggerated.

FIGS. 1A-1C illustrate various perspective views of an aerosol-generating device according to one or more example embodiments.

FIG. 2A illustrates the aerosol-generating device of FIGS. 1A-1C according to at least one example embodiment.

FIG. 2B illustrates a capsule for the aerosol-generating device of FIGS. 1A-1C according to at least one example embodiment.

FIGS. 2C-2D illustrate partially-disassembled views of the aerosol-generating device of FIGS. 1A-1C according to at least one example embodiment.

FIGS. 2E-2F illustrate cross-sectional views of the aerosol-generating device of FIGS. 1A-1C according to at least one example embodiment.

FIG. 3 illustrates electrical systems of an aerosol-generating device and a capsule according to one or more example embodiments.

FIG. 4 illustrates a heater voltage measurement circuit according to one or more example embodiments.

FIG. 5 illustrates a heater current measurement circuit according to one or more example embodiments.

FIGS. 6A-6B illustrates a compensation voltage measurement circuit and algorithm according to one or more example embodiments.

FIGS. 7A-7C illustrates a circuit diagrams illustrating a heating engine control circuit according to one or more example embodiments.

FIGS. 8A-8B illustrate methods of controlling a heater in a non-combustible aerosol-generating device according to one or more example embodiments.

FIG. 9 illustrates a block diagram illustrating a temperature heating engine control algorithm according to at least one or more example embodiments.

FIG. 10 illustrates a timing diagram of the methods illustrated in FIGS. 8A-8B one or more example embodiments.

FIGS. 11A and 11B illustrate a flow chart illustrating a method for controlling an aerosol-generating device according to example embodiments.

FIG. 12 is a flow chart illustrating a method for validating a capsule according to example embodiments.

FIG. 13 is a graph illustrating recorded waveforms for a valid capsule according to example embodiments.

FIG. 14 is an enlarged view of a portion of the recorded waveforms shown in FIG. 13 .

FIG. 15 is a graph illustrating recorded waveforms for a degraded and invalid capsule according to example embodiments.

FIG. 16 is an enlarged view of the waveforms shown in FIG. 15 .

FIG. 17 is a graph illustrating recorded waveforms for another example valid capsule according to example embodiments.

FIG. 18 is a graph illustrating a recorded waveforms for another invalid capsule according to example embodiments.

FIG. 19 is an enlarged view of the waveforms shown in FIG. 18 .

FIG. 20 is a flow chart illustrating a method for capsule reuse detection according to example embodiments.

FIG. 21 is a flow chart illustrating another method for capsule reuse detection according to example embodiments.

FIG. 22 is a graph illustrating an example comparison of recorded power target waveforms for new and reused capsules, according to example embodiments.

DETAILED DESCRIPTION

Some detailed example embodiments are disclosed herein. However, specific structural and functional details disclosed herein are merely representative for purposes of describing example embodiments. Example embodiments may, however, be embodied in many alternate forms and should not be construed as limited to only the example embodiments set forth herein.

Accordingly, while example embodiments are capable of various modifications and alternative forms, example embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that there is no intent to limit example embodiments to the particular forms disclosed, but to the contrary, example embodiments are to cover all modifications, equivalents, and alternatives thereof. Like numbers refer to like elements throughout the description of the figures.

It should be understood that when an element or layer is referred to as being “on,” “connected to,” “coupled to,” “attached to,” “adjacent to,” or “covering” another element or layer, it may be directly on, connected to, coupled to, attached to, adjacent to or covering the other element or layer or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly connected to,” or “directly coupled to” another element or layer, there are no intervening elements or layers present. Like numbers refer to like elements throughout the specification. As used herein, the term “and/or” includes any and all combinations or sub-combinations of one or more of the associated listed items.

It should be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, regions, layers and/or sections, these elements, regions, layers, and/or sections should not be limited by these terms. These terms are only used to distinguish one element, region, layer, or section from another region, layer, or section. Thus, a first element, region, layer, or section discussed below could be termed a second element, region, layer, or section without departing from the teachings of example embodiments.

Spatially relative terms (e.g., “beneath,” “below,” “lower,” “above,” “upper,” and the like) may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It should be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the term “below” may encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing various example embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “includes,” “including,” “comprises,” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, and/or elements, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, and/or groups thereof.

When the words “about” and “substantially” are used in this specification in connection with a numerical value, it is intended that the associated numerical value include a tolerance of ±10% around the stated numerical value, unless otherwise explicitly defined.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It will be further understood that terms, including those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Hardware may be implemented using processing or control circuitry such as, but not limited to, one or more processors, one or more Central Processing Units (CPUs), one or more microcontrollers, one or more arithmetic logic units (ALUs), one or more digital signal processors (DSPs), one or more microcomputers, one or more field programmable gate arrays (FPGAs), one or more System-on-Chips (SoCs), one or more programmable logic units (PLUs), one or more microprocessors, one or more Application Specific Integrated Circuits (ASICs), or any other device or devices capable of responding to and executing instructions in a defined manner.

One or more example embodiments may be described herein, in at least some instances, as being performed by an aerosol-generating device including at least one processor and a memory storing computer-executable instructions, wherein the at least one processor is configured to execute the computer-readable instructions to cause the aerosol-generating device to perform operations of one or more example embodiments. Additionally, the processor, memory and example algorithms, encoded as computer program code, may serve as means for providing or causing performance of operations discussed herein.

FIG. 1A is a front perspective view of an aerosol-generating device according to an example embodiment. FIG. 1B is a rear perspective view of the aerosol-generating device of FIG. 1A. FIG. 1C is an upstream perspective view of the aerosol-generating device of FIG. 1A. Referring to FIGS. 1A-C, an aerosol-generating device 10 is configured to receive and heat an aerosol-forming substrate to produce an aerosol. The aerosol-generating device 10 includes, inter alia, a front housing 1202, a rear housing 1204, and a bottom housing 1206 coupled to a frame 1208 (e.g., chassis). A door 1210 is also pivotally connected/attached to the front housing 1202. For instance, the door 1210 is configured to move or swing about a hinge 1212 and configured to reversibly engage/disengage with the front housing 1202 via a latch 1214 in order to transition between an open position and a closed position. The aerosol-forming substrate, which may be contained within a capsule 100 (e.g., FIG. 2 ), may be loaded into the aerosol-generating device 10 via the door 1210. During an operation of the aerosol-generating device 10, the aerosol produced may be drawn from the aerosol-generating device 10 via the aerosol outlet 1102 defined by the mouth-end segment 1104 of the mouthpiece 1100 (e.g., FIG. 2 ).

As illustrated in FIG. 1B, the aerosol-generating device 10 includes a first button 1218 and a second button 1220. The first button 1218 may be a pre-heat button, and the second button 1220 may be a power button (or vice versa). Additionally, one or both of the first button 1218 and the second button 1220 may include a light-emitting diode (LED) configured to emit a visible light when the first button 1218 and/or the second button 1220 is pressed. Where both of the first button 1218 and the second button 1220 includes an LED, the lights emitted may be of the same color or of different colors. The lights may also be of the same intensity or of different intensities. Furthermore, the lights may be configured as continuous lights or intermittent lights. For instance, the light in connection with the power button (e.g., second button 1220) may blink/flash to indicate that the power supply (e.g., battery) is low and in need charging. While the aerosol-generating device 10 is shown as having two buttons, it should be understood that more (e.g., three) or less buttons may be provided depending on the desired interface and functionalities.

The aerosol-generating device 10 may have a cuboid-like shape which includes a front face, a rear face opposite the front face, a first side face between the front face and the rear face, a second side face opposite the first side face, a downstream end face, and an upstream end face opposite the downstream end face. As used herein, “upstream” (and, conversely, “downstream”) is in relation to a flow of the aerosol, and “proximal” (and, conversely, “distal”) is in relation to an adult operator of the aerosol-generating device 10 during aerosol generation. Although the aerosol-generating device 10 is illustrated as having a cuboid-like shape (e.g., rounded rectangular cuboid) with a polygonal cross-section, it should be understood that example embodiments are not limited thereto. For instance, in some embodiments, the aerosol-generating device 10 may have a cylinder-like shape with a circular cross-section (e.g., for a circular cylinder) or an elliptical cross-section (e.g., for an elliptic cylinder).

As illustrated in FIG. 1C, the aerosol-generating device 10 includes an inlet insert 1222 configured to permit ambient air to enter the device body 1200 (e.g., FIG. 2 ). In an example embodiment, the inlet insert 1222 defines an orifice as an air inlet which is in fluidic communication with the aerosol outlet 1102. As a result, when a draw (e.g., a puff) or negative pressure is applied to the aerosol outlet 1102, ambient air will be pulled into the device body 1200 via the orifice in the inlet insert 1222. The size (e.g., diameter) of the orifice in the inlet insert 1222 made be adjusted, while also taking in account other variables (e.g., capsule 100) in the flow path, to provide the desired overall resistance-to-draw (RTD). In other embodiments, the inlet insert 1222 may be omitted altogether such that the air inlet is defined by the bottom housing 1206.

The aerosol-generating device 10 may additionally include a jack 1224 and a port 1226. In an example embodiment, the jack 1224 permits the downloading of operational information for research and development (R&D) purposes (e.g., via an RS232 cable). The port 1226 is configured to receive an electric current (e.g., via a USB/mini-USB cable) from an external power supply so as to charge an internal power supply within the aerosol-generating device 10. In addition, the port 1226 may also be configured to send data to and/or receive data (e.g., via a USB/mini-USB cable) from another aerosol-generating device or other electronic device (e.g., phone, tablet, computer). Furthermore, the aerosol-generating device 10 may be configured for wireless communication with another electronic device, such as a phone, via an application software (app) installed on that electronic device. In such an instance, an adult operator may control or otherwise interface with the aerosol-generating device 10 (e.g., locate the aerosol-generating device, check usage information, change operating parameters) through the app.

FIG. 2A is the front perspective view of the aerosol-generating device of FIGS. 1A-1C, wherein a mouthpiece 1100 and a capsule 100 are separated from the device body. Referring to FIG. 2 , the aerosol-generating device 10 includes a device body 1200 configured to receive a capsule 100 and a mouthpiece 1100. In an example embodiment, the device body 1200 defines a receptacle 1228 configured to receive the capsule 100. The receptacle 1228 may be in a form of a cylindrical socket with outwardly-extending, diametrically-opposed side slots to accommodate the electrical end sections/contacts of the capsule 100. However, it should be understood that the receptacle 1228 may be in other forms based on the shape/configuration of the capsule 100.

As noted supra, the device body 1200 includes a door 1210 configured to open to permit an insertion of the capsule 100 and the mouthpiece 1100 and configured to close to retain the capsule 100 and the mouthpiece 1100. The mouthpiece 1100 includes a mouth end (e.g., of the mouth-end segment 1104) and an opposing capsule end (e.g., of the capsule-end segment 1106). In an example embodiment, the capsule end is larger than the mouth end and configured to prevent a disengagement of the mouthpiece 1100 from the capsule 100 when the door 1210 of the device body 1200 is closed. When received/secured within the device body 1200 and ready for aerosol generation, the capsule 100 may be hidden from view while the mouth-end segment 1104 defining the aerosol outlet 1102 of the mouthpiece 1100 is visible. As illustrated in the figures, the mouth-end segment 1104 of the mouthpiece 1100 may extend from/through the downstream end face of the device body 1200. Additionally, the mouth-end segment 1104 of the mouthpiece 1100 may be closer to the front face of the device body 1200 than the rear face.

In some instances, the device body 1200 of the aerosol-generating device 10 may optionally include a mouthpiece sensor and/or a door sensor. The mouthpiece sensor may be disposed on a rim of the receptacle 1228 (e.g., adjacent to the front face of the device body 1200). The door sensor may be disposed on a portion of the front housing 1202 adjacent to the hinge 1212 and within the swing path of the door 1210. In an example embodiment, the mouthpiece sensor and the door sensor are spring-loaded (e.g., retractable) projections configured as safety switches. For instance, the mouthpiece sensor may be retracted/depressed (e.g., activated) when the mouthpiece 1100 is fully engaged with the capsule 100 loaded within the receptacle 1228. Additionally, the door sensor may be retracted/depressed (e.g., activated) when the door 1210 is fully closed. In such instances, the control circuitry of the device body 1200 may permit an electric current to be supplied to the capsule 100 to heat the aerosol-forming substrate therein (e.g., pre-heat permitted when the first button 1218 is pressed). Conversely, the control circuitry (e.g., a controller 2105) of the device body 1200 may prevent or cease the supply of electric current when the mouthpiece sensor and/or the door sensor is not activated or deactivated (e.g., released). Thus, the heating of the aerosol-forming substrate will not be initiated if the mouthpiece 1100 is not fully inserted and/or if the door 1210 is not fully closed. Similarly, the supply of electric current to the capsule 100 will be disrupted/halted if the door 1210 is opened during the heating of the aerosol-forming substrate.

The capsule 100, which will be discussed herein in more detail, generally includes a housing defining inlet openings, outlet openings, and a chamber between the inlet openings and the outlet openings. An aerosol-forming substrate is disposed within the chamber of the housing. Additionally, a heater may extend into the housing from an exterior thereof. The housing may include a body portion and an upstream portion. The body portion of the housing includes a proximal end and a distal end. The upstream portion of the housing may be configured to engage with the distal end of the body portion.

FIG. 2B illustrates a capsule for the aerosol-generating device of FIGS. 1A-1C according to at least one example embodiment.

An aerosol-forming substrate contained within the capsule 100 may be in the form of a first aerosol-forming substrate 160 a and a second aerosol-forming substrate 160 b. In an example embodiment, the first aerosol-forming substrate 160 a and the second aerosol-forming substrate 160 b are housed between a first cover 110 and a second cover 120. During the operation of the aerosol-generating device 10, the first aerosol-forming substrate 160 a and the second aerosol-forming substrate 160 b may be heated by a heater 336 to generate an aerosol. As will be discussed herein in more detail, the heater 336 includes a first end section 142, an intermediate section 144, and a second end section 146. Additionally, prior to the assembly of the capsule 100, the heater 336 may be mounted in the base portion 130 during a manufacturing process.

As illustrated, the first cover 110 of the capsule 100 defines a first upstream groove 112, a first recess 114, and a first downstream groove 116. The first upstream groove 112 and the first downstream groove 116 may each be in the form of a series of grooves. Similarly, the second cover 120 of the capsule 100 defines a second upstream groove, a second recess, and a second downstream groove 126. In an example embodiment, the second upstream groove, the second recess, and the second downstream groove 126 of the second cover 120 are the same as the first upstream groove 112, the first recess 114, and the first downstream groove 116, respectively, of the first cover 110. Specifically, in some instances, the first cover 110 and the second cover 120 are identical and complementary structures. In such instances, orienting the first cover 110 and the second cover 120 to face each other for engagement with the base portion 130 will result in a complementary arrangement. As a result, one part may be used interchangeably as the first cover 110 or the second cover 120, thus simplifying the method of manufacturing.

The first recess 114 of the first cover 110 and the second recess of the second cover 120 collectively form a chamber configured to accommodate the intermediate section 144 of the heater 336 when the first cover 110 and the second cover 120 are coupled with the base portion 130. The first aerosol-forming substrate 160 a and the second aerosol-forming substrate 160 b may also be accommodated within the chamber so as to be in thermal contact with the intermediate section 144 of the heater 336 when the capsule 100 is assembled. The chamber may have a longest dimension extending from at least one of the inlet openings (e.g., of the upstream passageway 162) to a corresponding one of the outlet openings (e.g., of the downstream passageway 166). In an example embodiment, the housing of the capsule 100 has a longitudinal axis, and the longest dimension of the chamber extends along the longitudinal axis of the housing.

The first downstream groove 116 of the first cover 110 and the second downstream groove 126 of the second cover 120 collectively form the downstream passageway 166. Similarly, the first upstream groove 112 of the first cover 110 and the second upstream groove of the second cover 120 collectively form the upstream passageway 162. The downstream passageway 166 and the upstream passageway 162 are dimensioned to be small or narrow enough to retain the first aerosol-forming substrate 160 a and the second aerosol-forming substrate 160 b within the chamber but yet large or wide enough to permit a passage of air and/or an aerosol therethrough when the first aerosol-forming substrate 160 a and the second aerosol-forming substrate 160 b are heated by the heater 336.

In one instance, each of the first aerosol-forming substrate 160 a and the second aerosol-forming substrate 160 b may be in a consolidated form (e.g., sheet, pallet, tablet) that is configured to maintain its shape so as to allow the first aerosol-forming substrate 160 a and the second aerosol-forming substrate 160 b to be placed in a unified manner within the first recess 114 of the first cover 110 and the second recess of the second cover 120, respectively. In such an instance, the first aerosol-forming substrate 160 a may be disposed on one side of the intermediate section 144 of the heater 336 (e.g., side facing the first cover 110), while the second aerosol-forming substrate 160 b may be disposed on the other side of the intermediate section 144 of the heater 336 (e.g., side facing the second cover 120) so as to substantially fill the first recess 114 of the first cover 110 and the second recess of the second cover 120, respectively, thereby sandwiching/embedding the intermediate section 144 of the heater 336 in between. Alternatively, one or both of the first aerosol-forming substrate 160 a and the second aerosol-forming substrate 160 b may be in a loose form (e.g., particles, fibers, grounds, fragments, shreds) that does not have a set shape but rather is configured to take on the shape of the first recess 114 of the first cover 110 and/or the second recess of the second cover 120 when introduced.

As noted supra, the housing of the capsule 100 may include the first cover 110, the second cover 120, and the base portion 130. When the capsule 100 is assembled, the housing may have a height (or length) of about 30 mm-40 mm (e.g., 35 mm), although example embodiments are not limited thereto. Additionally, each of the first recess 114 of the first cover 110 and the second recess of the second cover 120 may have a depth of about 1 mm-4 mm (e.g., 2 mm). In such an instance, the chamber collectively formed by the first recess 114 of the first cover 110 and the second recess of the second cover 120 may have an overall thickness of about 2 mm-8 mm (e.g., 4 mm). Along these lines, the first aerosol-forming substrate 160 a and the second aerosol-forming substrate 160 b, if in a consolidated form, may each have a thickness of about 1 mm-4 mm (e.g., 2 mm). As a result, the first aerosol-forming substrate 160 a and the second aerosol-forming substrate 160 b may be heated relatively quickly and uniformly by the intermediate section 144 of the heater 336.

The control circuitry may instruct a power supply to supply an electric current to the heater 336. The supply of current from the power supply may be in response to a manual operation (e.g., button-activation) or an automatic operation (e.g., draw/puff-activation). As a result of the current, the capsule 100 may be heated to generate an aerosol. In addition, the change in resistance of the heater may be used to monitor and control the aerosolization temperature. The aerosol generated may be drawn from the aerosol-generating device 10 via the mouthpiece 1100. In addition, the control circuitry (e.g., a controller 2105) may instruct a power supply to supply an electric current to the heater 336 to maintain a temperature of the capsule 100 between draws.

As discussed herein, an aerosol-forming substrate is a material or combination of materials that may yield an aerosol. An aerosol relates to the matter generated or output by the devices disclosed, claimed, and equivalents thereof. The material may include a compound (e.g., nicotine, cannabinoid), wherein an aerosol including the compound is produced when the material is heated. The heating may be below the combustion temperature so as to produce an aerosol without involving a substantial pyrolysis of the aerosol-forming substrate or the substantial generation of combustion byproducts (if any). Thus, in an example embodiment, pyrolysis does not occur during the heating and resulting production of aerosol. In other instances, there may be some pyrolysis and combustion byproducts, but the extent may be considered relatively minor and/or merely incidental.

The aerosol-forming substrate may be a fibrous material. For instance, the fibrous material may be a botanical material. The fibrous material is configured to release a compound when heated. The compound may be a naturally occurring constituent of the fibrous material. For instance, the fibrous material may be plant material such as tobacco, and the compound released may be nicotine. The term “tobacco” includes any tobacco plant material including tobacco leaf, tobacco plug, reconstituted tobacco, compressed tobacco, shaped tobacco, or powder tobacco, and combinations thereof from one or more species of tobacco plants, such as Nicotiana rustica and Nicotiana tabacum.

In some example embodiments, the tobacco material may include material from any member of the genus Nicotiana. In addition, the tobacco material may include a blend of two or more different tobacco varieties. Examples of suitable types of tobacco materials that may be used include, but are not limited to, flue-cured tobacco, Burley tobacco, Dark tobacco, Maryland tobacco, Oriental tobacco, rare tobacco, specialty tobacco, blends thereof, and the like. The tobacco material may be provided in any suitable form, including, but not limited to, tobacco lamina, processed tobacco materials, such as volume expanded or puffed tobacco, processed tobacco stems, such as cut-rolled or cut-puffed stems, reconstituted tobacco materials, blends thereof, and the like. In some example embodiments, the tobacco material is in the form of a substantially dry tobacco mass. Furthermore, in some instances, the tobacco material may be mixed and/or combined with at least one of propylene glycol, glycerin, sub-combinations thereof, or combinations thereof.

The compound may also be a naturally occurring constituent of a medicinal plant that has a medically-accepted therapeutic effect. For instance, the medicinal plant may be a cannabis plant, and the compound may be a cannabinoid. Cannabinoids interact with receptors in the body to produce a wide range of effects. As a result, cannabinoids have been used for a variety of medicinal purposes (e.g., treatment of pain, nausea, epilepsy, psychiatric disorders). The fibrous material may include the leaf and/or flower material from one or more species of cannabis plants such as Cannabis sativa, Cannabis indica, and Cannabis ruderalis. In some instances, the fibrous material is a mixture of 60-80% (e.g., 70%) Cannabis sativa and 20-40% (e.g., 30%) Cannabis indica.

Examples of cannabinoids include tetrahydrocannabinolic acid (THCA), tetrahydrocannabinol (THC), cannabidiolic acid (CBDA), cannabidiol (CBD), cannabinol (CBN), cannabicyclol (CBL), cannabichromene (CBC), and cannabigerol (CBG). Tetrahydrocannabinolic acid (THCA) is a precursor of tetrahydrocannabinol (THC), while cannabidiolic acid (CBDA) is precursor of cannabidiol (CBD). Tetrahydrocannabinolic acid (THCA) and cannabidiolic acid (CBDA) may be converted to tetrahydrocannabinol (THC) and cannabidiol (CBD), respectively, via heating. In an example embodiment, heat from a heater (e.g., heater 336 shown in FIG. 2B) may cause decarboxylation so as to convert the tetrahydrocannabinolic acid (THCA) in the capsule 100 to tetrahydrocannabinol (THC), and/or to convert the cannabidiolic acid (CBDA) in the capsule 100 to cannabidiol (CBD).

In instances where both tetrahydrocannabinolic acid (THCA) and tetrahydrocannabinol (THC) are present in the capsule 100, the decarboxylation and resulting conversion will cause a decrease in tetrahydrocannabinolic acid (THCA) and an increase in tetrahydrocannabinol (THC). At least 50% (e.g., at least 87%) of the tetrahydrocannabinolic acid (THCA) may be converted to tetrahydrocannabinol (THC) during the heating of the capsule 100. Similarly, in instances where both cannabidiolic acid (CBDA) and cannabidiol (CBD) are present in the capsule 100, the decarboxylation and resulting conversion will cause a decrease in cannabidiolic acid (CBDA) and an increase in cannabidiol (CBD). At least 50% (e.g., at least 87%) of the cannabidiolic acid (CBDA) may be converted to cannabidiol (CBD) during the heating of the capsule 100.

Furthermore, the compound may be or may additionally include a non-naturally occurring additive that is subsequently introduced into the fibrous material. In one instance, the fibrous material may include at least one of cotton, polyethylene, polyester, rayon, combinations thereof, or the like (e.g., in a form of a gauze). In another instance, the fibrous material may be a cellulose material (e.g., non-tobacco and/or non-cannabis material). In either instance, the compound introduced may include nicotine, cannabinoids, and/or flavorants. The flavorants may be from natural sources, such as plant extracts (e.g., tobacco extract, cannabis extract), and/or artificial sources. In yet another instance, when the fibrous material includes tobacco and/or cannabis, the compound may be or may additionally include one or more flavorants (e.g., menthol, mint, vanilla). Thus, the compound within the aerosol-forming substrate may include naturally occurring constituents and/or non-naturally occurring additives. In this regard, it should be understood that existing levels of the naturally occurring constituents of the aerosol-forming substrate may be increased through supplementation. For example, the existing levels of nicotine in a quantity of tobacco may be increased through supplementation with an extract containing nicotine. Similarly, the existing levels of one or more cannabinoids in a quantity of cannabis may be increased through supplementation with an extract containing such cannabinoids.

The first cover 110 and the second cover 120 also define a first furrow 118 and a second furrow 128, respectively. The first furrow 118 and the second furrow 128 collectively form a downstream furrow configured to accommodate the first annular member 150 a. Similarly, the base portion 130 defines an upstream furrow 138 configured to accommodate the second annular member 150 b. As noted supra, the base portion 130 includes an engagement assembly 136 configured to facilitate a connection with the first cover 110 and the second cover 120. The engagement assembly 136 may be an integrally formed part of the base portion 130. In an example embodiment, the base portion 130 defines a base outlet 134 in fluidic communication with the base inlet 132, and the engagement assembly 136 is in the form of a projecting rim/collar on each side of the base outlet 134. Additionally, each of the first cover 110 and the second cover 120 may define a slot configured to receive a corresponding projecting rim/collar of the engagement assembly 136. As a result, the first cover 110 and the second cover 120 (e.g., via their distal ends) may interlock with the engagement assembly 136 of the base portion 130 (while also interfacing with each other) to form the housing of the capsule 100.

The first cover 110 and the second cover 120 may be made of a liquid-crystal polymer, PEEK (polyetheretherketone) or aluminum, for example.

A sheet material may be cut or otherwise processed (e.g., stamping, electrochemical etching, die cutting, laser cutting) to produce the heater 336. The sheet material may be formed of one or more conductors configured to undergo Joule heating (which is also known as ohmic/resistive heating). Suitable conductors for the sheet material include an iron-based alloy (e.g., stainless steel, iron aluminides), a nickel-based alloy (e.g., nichrome), and/or a ceramic (e.g., ceramic coated with metal). For instance, the stainless steel may be a type known in the art as SS316L, although example embodiments are not limited thereto. The sheet material may have a thickness of about 0.1-0.3 mm (e.g., 0.15-0.25 mm). The heater 336 may have a resistance between 0.5-2.5 Ohms (e.g., 1-2 Ohms).

The heater 336 has a first end section 142, an intermediate section 144, and a second end section 146. The first end section 142 and the second end section 146 are configured to receive an electric current from a power supply during an activation of the heater 336. When the heater 336 is activated (e.g., so as to undergo Joule heating), the temperature of the first aerosol-forming substrate 160 a and the second aerosol-forming substrate 160 b may increase, and an aerosol may be generated and drawn or otherwise released through the downstream passageway 166 of the capsule 100. The first end section 142 and the second end section 146 may each include a fork terminal to facilitate an electrical connection with the power supply (e.g., via a connection bolt), although example embodiments are not limited thereto. Additionally, because the heater 336 may be produced from a sheet material, the first end section 142, the second end section 146, and the intermediate section 144 may be coplanar. Furthermore, the intermediate section 144 of the heater 336 may have a planar and winding form resembling a compressed oscillation or zigzag with a plurality of parallel segments (e.g., eight to sixteen parallel segments). However, it should be understood that other forms for the intermediate section 144 of the heater 336 are also possible (e.g., spiral form, flower-like form).

In an example embodiment, the heater 336 extends through the base portion 130. In such an instance, the terminus of each of the first end section 142 and the second end section 146 may be regarded as external segments of the heater 336 protruding from opposite sides of the base portion 130. In particular, the intermediate section 144 of the heater 336 may be on the downstream side of the base portion 130 and aligned with the base outlet 134. During manufacturing, the heater 336 may be embedded within the base portion 130 via injection molding (e.g., insert molding, over molding). For instance, the heater 336 may be embedded such that the intermediate section 144 is evenly spaced between the pair of projecting rims/collars of the engagement assembly 136.

Although the first end section 142 and the second end section 146 of the heater 336 are shown in the drawings as projections (e.g., fins) extending from the sides of the base portion 130, it should be understood that, in some example embodiments, the first end section 142 and the second end section 146 of the heater 336 may be configured so as to constitute parts of the side surface of the capsule 100. For instance, the exposed portions of the first end section 142 and the second end section 146 of the heater 336 may be dimensioned and oriented so as to be situated/folded against the sides of the base portion 130 (e.g., while also following the underlying contour of the base portion 130). As a result, the first end section 142 and the second end section 146 may constitute a first electrical contact and a second electrical contact, respectively, as well as parts of the side surface of the capsule 100.

FIG. 2C is a partially-disassembled view of the aerosol-generating device of FIGS. 1A-1C. FIG. 2D is a partially-disassembled view of the aerosol-generating device of FIG. 2 . Referring to FIGS. 2C-2D, the frame 1208 (e.g., metal chassis) serves as a foundation for the internal components of the aerosol-generating device 10, which may be attached either directly or indirectly thereto. With regard to structures/components shown in the figures and already discussed above, it should be understood that such relevant teachings are also applicable to this section and may not have been repeated in the interest of brevity. In an example embodiment, the bottom housing 1206 is secured to the upstream end of the frame 1208. Additionally, the receptacle 1228 (for receiving the capsule 100) may be mounted onto the front side of the frame 1208. Between the receptacle 1228 and the bottom housing 1206 is an inlet channel 1230 configured to direct an incoming flow of ambient air to the capsule 100 in the receptacle 1228. The inlet insert 1222 (e.g., FIG. 1C), through which the incoming air may flow, may be disposed in the distal end of the inlet channel 1230. Furthermore, the receptacle 1228 and/or the inlet channel 1230 may include a flow sensor (e.g., integrated flow sensor).

A covering 1232 and a power supply 1234 therein (e.g., FIG. 2E) may be mounted onto the rear side of the frame 1208. To establish an electrical connection with the capsule 100 (e.g., which is in the receptacle 1228 and covered by the capsule-end segment 1106 of the mouthpiece 1100), a first power terminal block 1236 a and a second power terminal block 1236 b may be provided to facilitate the supply of an electric current. For instance, the first power terminal block 1236 a and the second power terminal block 1236 b may establish the requisite electrical connection between the power supply 1234 and the capsule 100 via the first end section 142 and the second end section 146 of the heater 336. The first power terminal block 1236 a and/or the second power terminal block 1236 b may be formed of brass.

The aerosol-generating device 10 may also include a plurality of printed circuit boards (PCBs) configured to facilitate its operation. In an example embodiment, a first printed circuit board 1238 (e.g., bridge PCB for power and I2C) is mounted onto the downstream end of the covering 1232 for the power supply 1234. Additionally, a second printed circuit board 1240 (e.g., HMI PCB) is mounted onto the rear of the covering 1232. In another instance, a third printed circuit board 1242 (e.g., serial port PCB) is secured to the front of the frame 1208 and situated behind the inlet channel 1230. Furthermore, a fourth printed circuit board 1244 (e.g., USB-C PCB) is disposed between the rear of the frame 1208 and the covering 1232 for the power supply 1234. However, it should be understood that the example embodiments herein regarding the printed circuit boards should not be interpreted as limiting since the size, shapes, and locations thereof may vary depending on the desired features of the aerosol-generating device 10.

FIG. 2E is a cross-sectional view of the aerosol-generating device of FIGS. 1A-1C. FIG. 2F is another cross-sectional view of the aerosol-generating device of FIGS. 1A-1C. With regard to structures/components shown in the figures and already discussed above, it should be understood that such relevant teachings are also applicable to this section and may not have been repeated in the interest of brevity. Referring to FIGS. 2E-2F, the mouth-end segment 1104 of the mouthpiece 1100 is illustrated as defining an aerosol outlet 1102 in the form of a single outlet. However, it should be understood that example embodiments are not limited thereto. For instance, the aerosol outlet 102 may alternatively be in the form of a plurality of smaller outlets (e.g., two to six outlets). In one instance, the plurality of outlets may be in the form of four outlets. The outlets may be radially-arranged and/or outwardly-angled so as to release diverging streams of aerosol.

In an example embodiment, at least one of a filter or a flavor medium may be optionally disposed within the mouth-end segment 1104 of the mouthpiece 1100. In such an instance, a filter and/or a flavor medium will be downstream from the chamber 164 such that the aerosol generated therein passes through at least one of the filter or the flavor medium before exiting through the at least one aerosol outlet 1102. The filter may reduce or prevent particles from the aerosol-forming substrate (e.g., aerosol-forming substrate 160 a and/or aerosol-forming substrate 160 b) from being inadvertently drawn from the capsule 100. The filter may also help reduce the temperature of the aerosol in order to provide the desired mouth feel. The flavor medium (e.g., flavor beads) may release a flavorant when the aerosol passes therethrough so as to impart the aerosol with a desired flavor. The flavorant may be the same as described above in connection with the aerosol-forming substrate. Furthermore, the filter and/or the flavor medium may have a consolidated form or a loose form as described supra in connection with the aerosol-forming substrate.

The aerosol-generating device 10 may also include a third annular member 150 c seated within the receptacle 1228. The third annular member 150 c (e.g., resilient O-ring) is configured to establish an air seal when the base portion 130 of the capsule 100 is fully inserted into the receptacle 1228. As a result, most if not all of the air drawn into the receptacle 1228 will pass through the capsule 100, and any bypass flow around the capsule 100 will be minuscule if any. In an example embodiment, the first annular member 150 a, the second annular member 150 b, and/or the third annular member 150 c may be formed of clear silicone.

In addition to the printed circuit boards already discussed above, the aerosol-generating device 10 may also include a fifth printed circuit board 1246 (e.g., main PCB) disposed between the frame 1208 and the power supply 1234. The power supply 1234 may be a 900 mAh battery, although example embodiments are not limited thereto. Furthermore, a sensor 1248 may be disposed upstream from the capsule 100 to enhance an operation of the aerosol-generating device 10. For instance, the sensor 1248 may be an air flow sensor. In view of the sensor 1248 as well as the first button 1218 and the second button 1220, the operation of the aerosol-generating device 10 may be an automatic operation (e.g., puff-activated) or a manual operation (e.g., button-activated). In at least one example embodiment, the sensor may be a microelectromechanical system (MEMS) flow or pressure sensor or another type of sensor configured to measure air flow such as a hot-wire anemometer.

Upon activating the aerosol-generating device 10, the capsule 100 within the device body 1200 may be heated to generate an aerosol. In an example embodiment, the activation of the aerosol-generating device 10 may be triggered by the detection of an air flow by the sensor 1248 and/or the generation of a signal associated with the pressing of the first button 1218 and/or the second button 1220. With regard to the detection of an air flow, a draw or application of negative pressure on the aerosol outlet 1102 of the mouthpiece 1100 will pull ambient air into the device body 1200 via the inlet channel 1230, wherein the air may initially pass through an inlet insert 1222 (e.g., FIG. 1C). Once inside the device body 1200, the air travels through the inlet channel 1230 to the receptacle 1228 where it is detected by the sensor 1248. After the sensor 1248, the air continues through the receptacle 1228 and enters the capsule 100 via the base portion 130. Specifically, the air will flow through the base inlet 132 of the capsule 100 before passing through the upstream passageway 162 and into the chamber 164. Moreover, the control circuitry (e.g., a controller 2105) may instruct a power supply to supply an electric current to the heater 336 to maintain a temperature of the capsule 100 between draws.

The detection of the air flow by the sensor 1248 may cause the control circuitry to the power supply 1234 to supply an electric current to the capsule 100 via the first end section 142 and the second end section 146 of the heater 336. As a result, the temperature of the intermediate section 144 of the heater 336 will increase which, in turn, will cause the temperature of the aerosol-forming substrate (e.g., aerosol-forming substrate 160 a and/or aerosol-forming substrate 160 b) inside the chamber 164 to increase such that volatiles are released by the aerosol-forming substrate to produce an aerosol. The aerosol produced will be entrained by the air flowing through the chamber 164. In particular, the aerosol produced in the chamber 164 will pass through the downstream passageway 166 of the capsule 100 before exiting the aerosol-generating device 10 from the aerosol outlet 1102 of the mouthpiece 1100.

FIG. 3 illustrates electrical systems of an aerosol-generating device and a capsule according to one or more example embodiments.

Referring to FIG. 3 , the electrical systems include an aerosol-generating device electrical system 2100 and a capsule electrical system 2200. The aerosol-generating device electrical system 2100 may be included in the aerosol-generating device 10, and the capsule electrical system 2200 may be included in the capsule 100.

In the example embodiment shown in FIG. 3 , the capsule electrical system 2200 includes the heater 336.

The capsule electrical system 2200 may further include a body electrical/data interface (not shown) for transferring power and/or data between the aerosol-generating device 10 and the capsule 100. According to at least one example embodiment, the electrical contacts shown in FIG. 2B, for example, may serve as the body electrical interface, but example embodiments are not limited thereto.

The aerosol-generating device electrical system 2100 includes a controller 2105, a power supply 1234, device sensors or measurement circuits 2125, a heating engine control circuit 2127, aerosol indicators 2135, on-product controls 2150 (e.g., buttons 1218 and 1220 shown in FIG. 1B), a memory 2130, and a clock circuit 2128. In some example embodiments, the controller 2105, the power supply 1234, device sensors or measurement circuits 2125, the heating engine control circuit 2127, the memory 2130, and the clock circuit 2128 are on the same PCB (e.g., the main PCB 1246). The aerosol-generating device electrical system 2100 may further include a capsule electrical/data interface (not shown) for transferring power and/or data between the aerosol-generating device 10 and the capsule 100.

The power supply 1234 may be an internal power supply to supply power to the aerosol-generating device 10 and the capsule 100. The supply of power from the power supply 1234 may be controlled by the controller 2105 through power control circuitry (not shown). The power control circuitry may include one or more switches or transistors to regulate power output from the power supply 1234. The power supply 1234 may be a Lithium-ion battery or a variant thereof (e.g., a Lithium-ion polymer battery).

The controller 2105 may be configured to control overall operation of the aerosol-generating device 10. According to at least some example embodiments, the controller 2105 may include processing circuitry such as hardware including logic circuits; a hardware/software combination such as a processor executing software; or a combination thereof. For example, the processing circuitry more specifically may include, but is not limited to, a central processing unit (CPU), an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA), a System-on-Chip (SoC), a programmable logic unit, a microprocessor, application-specific integrated circuit (ASIC), etc.

In the example embodiment shown in FIG. 3 , the controller 2105 is illustrated as a microcontroller including: input/output (I/O) interfaces, such as general purpose input/outputs (GPIOs), inter-integrated circuit (I²C) interfaces, serial peripheral interface bus (SPI) interfaces, or the like; a multichannel analog-to-digital converter (ADC); and a clock input terminal. However, example embodiments should not be limited to this example. In at least one example implementation, the controller 2105 may be a microprocessor.

The memory 2130 is illustrated as being external to the controller 2105, in some example embodiments the memory 2130 may be on board the controller 2105.

The controller 2105 is communicatively coupled to the device sensors 2125, the heating engine control circuit 2127, aerosol indicators 2135, the memory 2130, the on-product controls 2150, the clock circuit 2128 and the power supply 1234.

The heating engine control circuit 2127 is connected to the controller 2105 via a GPIO (General Purpose Input/Output) pin. The memory 2130 is connected to the controller 2105 via a SPI (Serial Peripheral Interface) pin. The clock circuit 2128 is connected to a clock input pin of the controller 2105. The aerosol indicators 2135 are connected to the controller 2105 via an I²C (Inter-Integrated Circuit) interface pin and a SPI/GPIO pin. The device sensors 2125 are connected to the controller 2105 through respective pins of the multi-channel ADC.

The clock circuit 2128 may be a timing mechanism, such as an oscillator circuit, to enable the controller 2105 to track idle time, preheat length, aerosol-generating (draw) length, a combination of idle time and aerosol-generating (draw) length, a power-use time to determine a hot capsule alert (e.g., 30 s after instance has ended) or the like, of the aerosol-generating device 10. The clock circuit 2128 may also include a dedicated external clock crystal configured to generate the system clock for the aerosol-generating device 10.

The memory 2130 may be a non-volatile memory storing operational parameters and computer readable instructions for the controller 2105 to perform the algorithms described herein. In one example, the memory 2130 may be an electrically erasable programmable read-only memory (EEPROM), such as a flash memory or the like.

Still referring to FIG. 3 , the device sensors 2125 may include a plurality of sensor or measurement circuits configured to provide signals indicative of sensor or measurement information to the controller 2105. In the example shown in FIG. 3 , the device sensors 2125 include a heater current measurement circuit 21258, a heater voltage measurement circuit 21252, and a compensation voltage measurement circuit 21250. The electrical systems of FIG. 3 may further includes the sensors discussed with reference to FIGS. 1A-2F.

The heater current measurement circuit 21258 may be configured to output (e.g., voltage) signals indicative of the current through the heater 336. An example embodiment of the heater current measurement circuit 21258 will be discussed in more detail later with regard to FIG. 5 .

The heater voltage measurement circuit 21252 may be configured to output (e.g., voltage) signals indicative of the voltage across the heater 336. An example embodiment of the heater voltage measurement circuit 21252 will be discussed in more detail later with regard to FIG. 4 .

The compensation voltage measurement circuit 21250 may be configured to output (e.g., voltage) signals indicative of the resistance of electrical power interface (e.g., electrical connector) between the capsule 100 and the aerosol-generating device 10. In some example embodiments, the compensation voltage measurement circuit 21250 may provide compensation voltage measurement signals to the controller 2105. Example embodiments of the compensation voltage measurement circuit 21250 will be discussed in more detail later with regard to FIGS. 6A-6B.

As discussed above, the compensation voltage measurement circuit 21250, the heater current measurement circuit 21258 and the heater voltage measurement circuit 21252 are connected to the controller 2105 via pins of the multi-channel ADC. To measure characteristics and/or parameters of the aerosol-generating device 10 and the capsule 100 (e.g., voltage, current, resistance, temperature, or the like, of the heater 336), the multi-channel ADC at the controller 2105 may sample the output signals from the device sensors 2125 at a sampling rate appropriate for the given characteristic and/or parameter being measured by the respective device sensor.

The aerosol-generating device electrical system 2100 may include the sensor 1248 to measure airflow through the aerosol-generating device 10. In at least one example embodiment, the sensor may be a microelectromechanical system (MEMS) flow or pressure sensor or another type of sensor configured to measure air flow such as a hot-wire anemometer. In an example embodiment, the output of the sensor to measure airflow to the controller 2105 is instantaneous measurement of flow (in ml/s or cm³/s) via a digital interface or SPI. In other example embodiments, the sensor may be a hot-wire anemometer, a digital MEMS sensor or other known sensors. The flow sensor may be operated as a puff sensor by detecting a draw when the flow value is greater than or equal to 1 mL/s, and terminating a draw when the flow value subsequently drops to 0 mL/s. In another example, the flow sensor may be operated as a puff sensor by detecting a draw when the flow value is greater than or equal to 1 mL/s and terminating a draw when the flow value subsequently drops below 1 mL/s. In an example embodiment, the sensor 1248 may be a MEMS flow sensor based differential pressure sensor with the differential pressure (in Pascals) converted to an instantaneous flow reading (in mL/s) using a curve fitting calibration function or a Look Up Table (of flow values for each differential pressure reading). In another example embodiment, the flow sensor may be a capacitive pressure drop sensor.

The heating engine control circuit 2127 is connected to the controller 2105 via a GPIO pin. The heating engine control circuit 2127 is configured to control (enable and/or disable) the heater 336 of the aerosol-generating device 10 by controlling power to the heater 336.

The controller 2105 may control the aerosol indicators 2135 to indicate statuses and/or operations of the aerosol-generating device 10 to an adult operator. The aerosol indicators 2135 may be at least partially implemented via a light guide and may include a power indicator (e.g., LED) that may be activated when the controller 2105 senses a button pressed by the adult operator. The aerosol indicators 2135 may also include a vibrator, speaker, or other feedback mechanisms, and may indicate a current state of an adult operator-controlled aerosol generating parameter (e.g., aerosol volume).

Still referring to FIG. 3 , the controller 2105 may control power to the heater 336 to heat the aerosol-forming substrate in accordance with a heating profile (e.g., heating based on volume, temperature, flavor, or the like). The heating profile may be determined based on empirical data and may be stored in the memory 2130 of the aerosol-generating device 10.

FIG. 4 illustrates an example embodiment of the heater voltage measurement circuit 21252.

Referring to FIG. 4 , the heater voltage measurement circuit 21252 includes a resistor 3702 and a resistor 3704 connected in a voltage divider configuration between a terminal configured to receive an input voltage signal COIL_OUT and ground. The resistances of the resistor 3702 and the resistor 3704 may be 8.2 kiloohms and 3.3 kiloohms, respectively. The input voltage signal COIL_OUT is the voltage input to (voltage at an input terminal of) the heater 336. A node N3716 between the resistor 3702 and the resistor 3704 is coupled to a positive input of an operational amplifier (Op-Amp) 3708. A capacitor 3706 is connected between the node N3716 and ground to form a low-pass filter circuit (an R/C filter) to stabilize the voltage input to the positive input of the Op-Amp 3708. The capacitance of the capacitor 3706 may be 18 nanofarads, for example. The filter circuit may also reduce inaccuracy due to switching noise induced by PWM signals used to energize the heater 336, and have the same phase response/group delay for both current and voltage.

The heater voltage measurement circuit 21252 further includes resistors 3710 and 3712 and a capacitor 3714. The resistor 3712 is connected between node N3718 and a terminal configured to receive an output voltage signal COIL_RTN and may have a resistance of 8.2 kiloohms, for example. The output voltage signal COIL_RTN is the voltage output from (voltage at an output terminal of) the heater 336.

Resistor 3710 and capacitor 3714 are connected in parallel between a node N3718 and an output of the Op-Amp 3708. The resistor 3710 may have a resistance of 3.3 kiloohms and the capacitor 3714 may have a capacitance of 18 nanofarads, for example. A negative input of the Op-Amp 3708 is also connected to node N3718. The resistors 3710 and 3712 and the capacitor 3714 are connected in a low-pass filter circuit configuration.

The heater voltage measurement circuit 21252 utilizes the Op-Amp 3708 to measure the voltage differential between the input voltage signal COIL_OUT and the output voltage signal COIL_RTN, and output a scaled heater voltage measurement signal COIL_VOL that represents the voltage across the heater 336. The heater voltage measurement circuit 21252 outputs the scaled heater voltage measurement signal COIL_VOL to an ADC pin of the controller 2105 for digital sampling and measurement by the controller 2105.

The gain of the Op-Amp 3708 may be set based on the surrounding passive electrical elements (e.g., resistors and capacitors) to improve the dynamic range of the voltage measurement. In one example, the dynamic range of the Op-Amp 3708 may be achieved by scaling the voltage so that the maximum voltage output matches the maximum input range of the ADC (e.g., about 2.5V). In at least one example embodiment, the scaling may be about 402 mV per V, and thus, the heater voltage measurement circuit 21252 may measure up to about 2.5V/0.402V=6.22V.

The voltage signals COIL_OUT and COIL_RTN are clamped by diodes 3720 and 3722, respectively, to reduce risk of damage due to electrostatic discharge (ESD) events.

In some example embodiments, four wire/Kelvin measurement may be used and the voltage signals COIL_OUT and COIL_RTN may be measured at measurement contact points (also referred to as voltage sensing connections (as opposed to main power contacts)) to take into account the contact and bulk resistances of an electrical power interface (e.g., electrical connector) between the heater 336 and the aerosol-generating device 10.

FIG. 5 illustrates an example embodiment of the heater current measurement circuit 21258 shown in FIG. 3 .

Referring to FIG. 5 , an output current signal COIL_RTN_I is input to a four terminal (4T) measurement resistor 3802 connected to ground. The differential voltage across the four terminal measurement resistor 3802 is scaled by an Op-Amp 3806, which outputs a heater current measurement signal COIL_CUR indicative of the current through the heater 336. The heater current measurement signal COIL_CUR is output to an ADC pin of the controller 2105 for digital sampling and measurement of the current through the heater 336 at the controller 2105.

In the example embodiment shown in FIG. 5 , the four terminal measurement resistor 3802 may be used to reduce error in the current measurement using a four wire/Kelvin current measurement technique. In this example, separation of the current measurement path from the voltage measurement path may reduce noise on the voltage measurement path.

The gain of the Op-Amp 3806 may be set to improve the dynamic range of the measurement. In this example, the scaling of the Op-Amp 3806 may be about 0.820 V/A, and thus, the heater current measurement circuit 21258 may measure up to about 2.5 V/(0.820 V/A)=3.5 A.

Referring to FIG. 5 in more detail, a first terminal of the four terminal measurement resistor 3802 is connected to a terminal of the heater 336 to receive the output current signal COIL_RTN_I. A second terminal of the four terminal measurement resistor 3802 is connected to ground. A third terminal of the four terminal measurement resistor 3802 is connected to a low-pass filter circuit (R/C filter) including resistor 3804, capacitor 3808 and resistor 3810. The resistance of the resistor 3804 may be 100 ohms, the resistance of the resistor 3810 may be 8.2 kiloohms and the capacitance of the capacitor 3808 may be 3.3. nanofarads, for example.

The output of the low-pass filter circuit is connected to a positive input of the Op-Amp 3806. The low-pass filter circuit may reduce inaccuracy due to switching noise induced by the PWM signals applied to energize the heater 336, and may also have the same phase response/group delay for both current and voltage.

The heater current measurement circuit 21258 further includes resistors 3812 and 3814 and a capacitor 3816. The resistors 3812 and 3814 and the capacitor 3816 are connected to the fourth terminal of the four terminal measurement resistor 3802, a negative input of the Op-Amp 3806 and an output of the Op-Amp 3806 in a low-pass filter circuit configuration, wherein the output of the low-pass filter circuit is connected to the negative input of the Op-Amp 3806. The resistors 3812 and 3814 may have resistances of 100 ohms and 8.2 kiloohms, respectively, and the capacitor 3816 may have a capacitance of 3.3. nanofarads, for example.

The Op-Amp 3806 outputs a differential voltage as the heater current measurement signal COIL_CUR to an ADC pin of the controller 2105 for sampling and measurement of the current through the heater 336 by the controller 2105.

According to at least this example embodiment, the configuration of the heater current measurement circuit 21258 is similar to the configuration of the heater voltage measurement circuit 21252, except that the low-pass filter circuit including resistors 3804 and 3810 and the capacitor 3808 is connected to a terminal of the four terminal measurement resistor 3802 and the low-pass filter circuit including the resistors 3812 and 3814 and the capacitor 3816 is connected to another terminal of the four terminal measurement resistor 3802.

The controller 2105 may average multiple samples (e.g., of voltage) over a time window (e.g., about 1 ms) corresponding to the ‘tick’ time (iteration time of a control loop) used in the aerosol-generating device 10, and convert the average to a mathematical representation of the voltage across and current through the heater 336 through application of a scaling value. The scaling value may be determined based on the gain settings implemented at the respective Op-Amps, which may be specific to the hardware of the aerosol-generating device 10.

The controller 2105 may filter the converted voltage and current measurements using, for example, a three tap moving average filter to attenuate measurement noise. The controller 2105 may then use the filtered measurements to calculate: resistance R_(HEATER) of the heater 336 (R_(HEATER)=COIL_VOL/COIL_CUR), power P_(HEATER) applied to the heater 336 (P_(HEATER)=COIL_VOL*COIL_CUR) or the like.

According to one or more example embodiments, the gain settings of the passive elements of the circuits shown in FIGS. 4 and/or 5 may be adjusted to match the output signal range to the input range of the controller 2105.

FIG. 6A illustrates electrical systems of an aerosol-generating device including a separate compensation voltage measurement circuit according to one or more example embodiments.

As shown in FIG. 6A, a contact interface between the heater 336 and the aerosol-generating device electrical system 2100 includes a four wire/Kelvin arrangement having an input power contact 6100, an input measurement contact 6200, an output measurement contact 6300 and an output power contact 6400.

A voltage measurement circuit 21252A receives a measurement voltage COIL_OUT_MEAS at the input measurement contact 6200 and an output measurement voltage COIL_RTN_MEAS at the output measurement contact 6300. The voltage measurement circuit 21252A is the same circuit as the voltage measurement circuit 21252 illustrated in FIG. 4 and outputs the scaled heater voltage measurement signal COIL_VOL. While in FIG. 4 COIL_OUT and COIL_RTN are illustrated, it should be understood that in example embodiments without a separate compensation voltage measurement circuit, the voltage measurement circuit 21252 may receive voltages at the input and output measurement contacts 6200, 6300 instead of the input and output power contacts 6100, 6400.

The systems shown in FIG. 6A further include the compensation voltage measurement circuit 21250. The compensation voltage measurement circuit 21250 is the same as the voltage measurement circuit 21252A except the compensation voltage measurement circuit 21250 receives the voltage COIL_OUT at the input power contact 6100 and receives the voltage COIL_RTN at the output power contact 6400 and outputs a compensation voltage measurement signal VCOMP.

The current measurement circuit 21258 receives the output current signal COIL_RTN_I at the output power contact 6400 and outputs the heater current measurement signal COIL_CUR.

FIG. 6B illustrates a method of the using a compensation voltage measurement signal to adjust a target power for a heater according to example embodiments.

The controller 2105 may perform the method shown in FIG. 6B.

At S6500, the controller starts a power delivery loop for the heater. At 6505, the controller pulls the operating parameters (e.g., heating engine control circuit threshold voltage, power loss threshold and wetting timer limit) from the memory.

At 6510, the controller determines whether power lost at the contacts PCONTACT exceeds a loss threshold. The controller may determine the power lost at the contacts PCONTACT as follows:

PCONTACT=abs((VCOMP*COIL_CUR)˜(COIL_VOL*COIL_CUR))

The loss threshold may be an absolute value (e.g., 3 W) or a percentage of the power applied to the heater (e.g., 25%).

If the controller determines the power lost PCONTACT is equal to or less than the loss threshold, the controller clears a wetting flag at S6515. The controller monitors the compensation voltage measurement signal VCOMP at S6520 and determines whether the compensation voltage measurement signal VCOMP exceeds a threshold voltage VMAX at S6525. The threshold voltage VMAX may be the rated voltage of the heating engine control circuit 2127.

If the controller determines the compensation voltage measurement signal VCOMP does not exceed the threshold voltage VMAX, the controller proceeds to the next iteration (i.e., next tick time) at S6530. If the controller determines the compensation voltage measurement signal VCOMP exceeds the threshold voltage VMAX, the controller reduces the heater power target for the next iteration at S6532 and proceeds to the next iteration at 6530.

Thus, if the power loss PCONTACT is less than the loss threshold, the controller may reduce the applied power to reduce a contact heating effect.

Returning back to 56510, if the controller determines the power lost PCONTACT is greater than the loss threshold, the controller determines if a wetting flag is set at 6535. If the controller determines the wetting flag is set at S6535, the controller terminates heating (e.g., does not supply power to the heater) at S6550.

If the controller determines the wetting flag is not set at S6535, the controller determines whether a wetting timer is running at S6540. The wetting time is used to permit an increased power loss for a desired/selected time period (e.g., 200 ms).

If the controller determines the wetting timer is not running, the controller starts the wetting timer at S6545 and then proceeds to monitor the compensation voltage measurement signal VCOMP at 6520.

If the controller determines the wetting timer is running at S6540, the controller determines whether the wetting timer has expired at S6555. If the controller determines the wetting timer is not expired, the controller proceeds to monitor the compensation voltage measurement signal VCOMP at S6520. Thus, the power loss in the contacts PCONTACT being above the power loss threshold is permitted if the wetting timer is still running.

If the controller determines the wetting timer is expired, the controller sets the wetting flag at 6560. The controller then reduces a heater power target at S6565 such that the power loss in the contacts PCONTACT falls below the loss threshold and the controller proceeds to monitor the compensation voltage measurement signal VCOMP at 6520. More specifically, the controller sets an upper power limit that can be used by the PID controller (i.e., instead of the PID loop being able to use a full power range it is restricted to a lower range such as 6 W instead of 12 W). The controller continues to use the same temperature error input, but responds more slowly since an upper power limit is lowered.

In other example embodiments, a controller may change the temperature target.

Contact resistances change with temperature (and may alternatively go down due to “wetting current” removing an oxidation layer of the contact) and, as a result, a proportion of power lost in the power contacts may change during use. By compensating for power loss at the contacts, the electrical systems improve the delivery of power to the heater (e.g., a latency to achieve a heater temperature can be reduced by increasing power once a wetting effect has taken place).

On each subsequent iteration of the power delivery loop shown in FIG. 6B, the controller 2105 may re-enter a ‘wetting’ process (e.g., to respond to a change in contact forces), however, the wetting flag is used to ensure that the controller does not continually restart the process.

FIGS. 7A-7C is a circuit diagram illustrating a heating engine control circuit according to example embodiments. The heating engine control circuit shown in FIGS. 7A-7C is an example of the heating engine control circuit 2127 shown in FIG. 3 .

The heating engine control circuit includes a boost converter circuit 7020 (FIG. 7A), a first stage 7040 (FIG. 7B) and a second stage 7060 (FIG. 7C).

The boost converter circuit 7020 is configured to create a voltage signal VGATE (e.g., 9V supply) (also referred to as a power signal or input voltage signal) from a voltage source BATT to power the first stage 7040 based on a first power enable signal PWR_EN_VGATE (also referred to as a shutdown signal). The controller may generate the first power enable signal PWR_EN_VGATE to have a logic high level when the aerosol-generating device is ready to be used. In other words, the first power enable signal PWR_EN_VGATE has a logic high level when at least the controller detects that a capsule is properly connected to the aerosol-generating device. In other example embodiments, the first power enable signal PWR_EN_VGATE has a logic high level when the controller detects that a capsule is properly connected to the aerosol-generating device and the controller detects an action such as a button being pressed.

The first stage 7040 utilizes the input voltage signal VGATE from the boost converter circuit 7020 to drive the heating engine control circuit 2127. The first stage 7040 and the second stage 7060 form a buck-boost converter circuit.

In the example embodiment shown in FIG. 7A, the boost converter circuit 7020 generates the input voltage signal VGATE only if the first enable signal PWR_EN_VGATE is asserted (present). The controller 2105 may VGATE to cut power to the first stage 7040 by de-asserting (stopping or terminating) the first enable signal PWR_EN_VGATE. The first enable signal PWR_EN_VGATE may serve as a device state power signal for performing an aerosol-generating-off operation at the device 1000. In this example, the controller 2105 may perform an aerosol-generating-off operation by de-asserting the first enable signal PWR_EN_VGATE, thereby disabling power to the first stage 7040, the second stage 7060 and the heater 336. The controller 2105 may then enable aerosol-generating at the device 1000 by again asserting the first enable signal PWR_EN_VGATE to the boost converter circuit 7020.

The controller 2105 may generate the first enable signal PWR_EN_VGATE at a logic level such that boost converter circuit 7020 outputs the input voltage signal VGATE having a high level (at or approximately 9V) to enable power to the first stage 7040 and the heater 336 in response to aerosol-generating conditions at the device 1000. The controller 2105 may generate the first enable signal PWR_EN_VGATE at another logic level such that boost converter circuit 7020 outputs the input voltage signal VGATE having a low level (at or approximately 0V) to disable power to the first stage 7040 and the heater 336, thereby performing a heater-off operation.

Referring in more detail to the boost converter circuit 7020 in FIG. 7A, a capacitor C36 is connected between the voltage source BATT and ground. The capacitor C36 may have a capacitance of 10 microfarads.

A first terminal of inductor L1006 is connected to node Node1 between the voltage source BATT and the capacitor C36. The inductor L1006 serves as the main storage element of the boost converter circuit 7020. The inductor L1006 may have an inductance of 10 microhenrys.

Node 1 is connected to a voltage input pin A1 a boost converter chip U11. In some example embodiments, the boost converter chip may be a TPS61046.

A second terminal of the inductor L1006 is connected to a switch pin SW of the boost converter chip U11. An enable pin EN of the booster converter chip U11 is configured to receive the first enable signal PWR_EN_VGATE from the controller 2105.

In the example shown in FIG. 7A, the boost converter chip U11 serves as the main switching element of the boost converter circuit 7020.

A resistor R53 is connected between the enable pin EN of the booster converter chip U11 and ground to act as a pull-down resistor to ensure that operation of the heater 336 is prevented when the first enable signal PWR_EN_GATE is in an indeterminate state. The resistor R53 may have a resistance of 100 kiloohms in some example embodiments.

A voltage output pin VOUT of the boost converter chip U11 is connected to a first terminal of a resistor R49 and first terminal of a capacitor C58. A second terminal of the capacitor C58 is connected to ground. A voltage output by the voltage output pin VOUT is the input voltage signal VGATE.

A second terminal of the resistor R49 and a first terminal of a resistor R51 are connected at a second node Node2. The second node Node2 is connected to a feedback pin FB of the booster converter chip U11. The booster converter chip U11 is configured to produce the input voltage signal VGATE at about 9V using the ratio of the resistance of the resistor R49 to the resistance of the resistor R51. In some example embodiments, the resistor R49 may have a resistance of 680 kiloohms and the resistor R51 may have a resistance of 66.5 kiloohms.

The capacitors C36 and C58 operate as smoothing capacitors and may have capacitances of 10 microfarads and 4.7 microfarads, respectively. The inductor L1006 may have an inductance selected based on a desired output voltage (e.g., 9V).

Referring now to FIG. 7B, the first stage 7040 receives the input voltage signal VGATE and a second enable signal COIL_Z. The second enable signal is a pulse-width-modulation (PWM) signal and is an input to the first stage 7040.

The first stage 7040 includes, among other things, an integrated gate driver U6 configured to convert low-current signal(s) from the controller 2105 to high-current signals for controlling switching of transistors of the first stage 7040. The integrated gate driver U6 is also configured to translate voltage levels from the controller 2105 to voltage levels required by the transistors of the first stage 7040. In the example embodiment shown in FIG. 7B, the integrated gate driver U6 is a half-bridge driver. However, example embodiments should not be limited to this example.

In more detail, the input voltage signal VGATE from the boost converter circuit 7020 is input to the first stage 7040 through a filter circuit including a resistor R22 and a capacitor C32. The resistor R22 may have a resistance of 10 ohms and the capacitor C32 may have a capacitance of 1 microfarad.

The filter circuit including the resistor R22 and the capacitor C32 is connected to the VCC pin (pin 4) of the integrated gate driver U6 and the anode of Zener diode D2 at node Node3. The second terminal of the capacitor C32 is connected to ground. The anode of the Zener diode D2 is connected to a first terminal of capacitor C32 and a boost pin BST (pin 1) of the integrated gate driver U6 at node Node7. A second terminal of the capacitor C31 is connected to the switching node pin SWN (pin 7) of the integrated gate driver U6 and between transistors Q2 and Q3 at node Node8. In the example embodiment shown in FIG. 7B, the Zener diode D2 and the capacitor C31 form part of a boot-strap charge-pump circuit connected between the input voltage pin VCC and the boost pin BST of the integrated gate driver U6. Because the capacitor C31 is connected to the input voltage signal VGATE from the boost converter circuit 7020, the capacitor C31 charges to a voltage almost equal to the input voltage signal VGATE through the diode D2. The capacitor C31 may have a capacitance of 220 nanofarads.

Still referring to FIG. 7B, a resistor R25 is connected between the high side gate driver pin DRVH (pin 8) and the switching node pin SWN (pin 7). A first terminal of a resistor R29 is connected to the low side gate driver pin DRVL at a node Node9. A second terminal of the resistor R29 is connected to ground.

A resistor R23 and a capacitor C33 form a filter circuit connected to the input pin IN (pin 2) of the integrated gate driver U6. The filter circuit is configured to remove high frequency noise from the second heater enable signal COIL_Z input to the input pin IN. The second heater enable signal COIL_Z is a PWM signal from the controller 2105. Thus, the filter circuit is designed to filter out high frequency components of a PWM square wave pulse train, slightly reduces the rise and fall times on the square wave edges so that transistors are turned on and off gradually.

A resistor R24 is connected to the filter circuit and the input pin IN at node Node10. The resistor R24 is used as a pull-down resistor, such that if the second heater enable signal COIL_Z is floating (or indeterminate), then the input pin IN of the integrated gate driver U6 is held at a logic low level to prevent activation of the heater 336.

A resistor R30 and a capacitor C37 form a filter circuit connected to a pin OD (pin 3) of the integrated gate driver U6. The filter circuit is configured to remove high frequency noise from the input voltage signal VGATE input to the pin OD.

A resistor R31 is connected to the filter circuit and the pin OD at node Node11. The resistor R31 is used as a pull-down resistor, such that if the input voltage signal VGATE is floating (or indeterminate), then the pin OD of the integrated gate driver U6 is held at a logic low level to prevent activation of the heater 336. The signal output by the filter circuit formed by the resistor R30 and the capacitor C37 is referred to as filtered signal GATEON. R30 and R31 are also a divider circuit such that the signal VGATE is divided down to ˜2.5V for a transistor driver chip input.

The transistors Q2 and Q3 field-effect transistors (FETs) connected in series between the voltage source BATT and ground. In addition, a first terminal of an inductor L3 is connected to the voltage source BATT. A second terminal of the inductor L3 is connected to a first terminal of a capacitor C30 and to a drain of the transistor Q2 at a node Node12. A second terminal of the capacitor C30 is connected to ground. The inductor L3 and the capacitor C30 form a filter to reduce and/or prevent transient spikes from the voltage source BATT.

The gate of the transistor Q3 is connected to the low side gate driver pin DRVL (pin 5) of the integrated gate driver U6, the drain of the transistor Q3 is connected to the switching node pin SWN (pin 7) of the integrated gate driver U6 at node Node8, and the source of the transistor Q3 is connected to ground GND. When the low side gate drive signal output from the low side gate driver pin DRVL is high, the transistor Q3 is in a low impedance state (ON), thereby connecting the node Node8 to ground.

As mentioned above, because the capacitor C31 is connected to the input voltage signal VGATE from the boost converter circuit 7020, the capacitor C31 charges to a voltage equal or substantially equal to the input voltage signal VGATE through the diode D2.

When the low side gate drive signal output from the low side gate driver pin DRVL is low, the transistor Q3 switches to the high impedance state (OFF), and the high side gate driver pin DRVH (pin 8) is connected internally to the boost pin BST within the integrated gate driver U6. As a result, transistor Q2 is in a low impedance state (ON), thereby connecting the switching node SWN to the voltage source BATT to pull the switching node SWN (Node 8) to the voltage of the voltage source BATT.

In this case, the node Node7 is raised to a bootstrap voltage V(BST)≈V(VGATE)+V(BATT), which allows the gate-source voltage of the transistor Q2 to be the same or substantially the same as the voltage of the input voltage signal VGATE (e.g., V(VGATE)) regardless (or independent) of the voltage from the voltage source BATT. The circuit arrangement ensures that the BST voltage is not changed as the voltage of the voltage source drops, i.e., the transistors are efficiently switched even as the voltage of the voltage source BATT changes.

As a result, the switching node SWN (Node 8) provides a high current switched signal that may be used to generate a voltage output to the second stage 7060 (and a voltage output to the heater 336) that has a maximum value equal to the battery voltage source BATT, but is otherwise substantially independent of the voltage output from the battery voltage source BATT.

A first terminal of a capacitor C34 and an anode of a Zener diode D4 are connected to an output terminal to the second stage 7060 at a node Node13. The capacitor C34 and a resistor R28 are connected in series. A second terminal of the capacitor C34 and a first terminal of the resistor R28 are connected. A cathode of the Zener diode D4 and a second terminal of the resistor R28 are connected to ground.

The capacitor C34, the Zener diode D4 and the resistor R28 form a back EMF (electric and magnetic fields) prevention circuit that prevents energy from an inductor L4 (shown in FIG. 7C) from flowing back into the first stage 7040.

The resistor R25 is connected between the gate of the transistor Q2 and the drain of the transistor Q3. The resistor R25 serves as a pull-down resistor to ensure that the transistor Q2 switches to a high impedance more reliably.

The output of the first stage 7040 is substantially independent of the voltage of the voltage source and is less than or equal to the voltage of the voltage source. When the second heater enable signal COIL_Z is at 100% PWM, the transistor Q2 is always activated, and the output of the first stage 7040 is the voltage of the voltage source or substantially the voltage of the voltage source.

FIG. 7C illustrates the second stage 7060. The second stage 7060 boosts the voltage of the output signal from the first stage 7040. More specifically, when the second heater enable signal COIL_Z is at a constant logic high level, a third enable signal COIL_X may be activated to boost the output of the first stage 7040. The third enable signal COIL_X is a PWM signal from the controller 2105. The controller 2105 controls the widths of the pulses of the third enable signal COIL_X to boost the output of the first stage 7040 and generate the input voltage signal COIL_OUT. When the third enable signal COIL_X is at a constant low logic level, the output of the second stage 7060 is the output of the first stage 7040.

The second stage 7060 receives the input voltage signal VGATE, the third enable signal COIL_X and the filtered signal GATEON.

The second stage 7060 includes, among other things, an integrated gate driver U7 configured to convert low-current signal(s) from the controller 2105 to high-current signals for controlling switching of transistors of the second stage 7060. The integrated gate driver U7 is also configured to translate voltage levels from the controller 2105 to voltage levels required by the transistors of the second stage 7060. In the example embodiment shown in FIG. 7B, the integrated gate driver U7 is a half-bridge driver. However, example embodiments should not be limited to this example.

In more detail, the input voltage signal VGATE from the boost converter circuit 7020 is input to the second stage 7060 through a filter circuit including a resistor R18 and a capacitor C28. The resistor R18 may have a resistance of 10 ohms and the capacitor C28 may have a capacitance of 1 microfarad.

The filter circuit including the resistor R18 and the capacitor C28 is connected to the VCC pin (pin 4) of the integrated gate driver U7 and the anode of Zener diode D1 at node Node14. The second terminal of the capacitor C28 is connected to ground. The anode of the Zener diode D2 is connected to a first terminal of capacitor C27 and a boost pin BST (pin 1) of the integrated gate driver U7 at node Node15. A second terminal of the capacitor C27 is connected to the switching node pin SWN (pin 7) of the integrated gate driver U7 and between transistors Q1 and Q4 at node Node16.

In the example embodiment shown in FIG. 7C, the Zener diode D1 and the capacitor C27 form part of a boot-strap charge-pump circuit connected between the input voltage pin VCC and the boost pin BST of the integrated gate driver U7. Because the capacitor C27 is connected to the input voltage signal VGATE from the boost converter circuit 7020, the capacitor C27 charges to a voltage almost equal to the input voltage signal VGATE through the diode D1. The capacitor C31 may have a capacitance of 220 nanofarads.

Still referring to FIG. 7C, a resistor R21 is connected between the high side gate driver pin DRVH (pin 8) and the switching node pin SWN (pin 7). A gate of the transistor Q4 is connected to the low side gate driver pin DRVL (pin 5) of the integrated date driver U7.

A first terminal of the inductor L4 is connected to the output of the first stage 7040 and a second terminal of the inductor L4 is connected to the node Node16. The inductor L4 serves as the main storage element of the output of the first stage 7040. In example operation, when the integrated gate driver U7 outputs a low level signal from low side gate driver pin DRVL (pin 5), the transistor Q4 switches to a low impedance state (ON), thereby allowing current to flow through inductor L4 and transistor Q4. This stores energy in inductor L4, with the current increasing linearly over time. The current in the inductor is proportional to the switching frequency of the transistors (which is controlled by the third heater enable signal COIL_X).

A resistor R10 and a capacitor C29 form a filter circuit connected to the input pin IN (pin 2) of the integrated gate driver U7. The filter circuit is configured to remove high frequency noise from the third heater enable signal COIL_X input to the input pin IN.

A resistor R20 is connected to the filter circuit and the input pin IN at node Node17. The resistor R20 is used as a pull-down resistor, such that if the third heater enable signal COIL_X is floating (or indeterminate), then the input pin IN of the integrated gate driver U7 is held at a logic low level to prevent activation of the heater 336.

A resistor R30 and a capacitor C37 form a filter circuit connected to a pin OD (pin 3) of the integrated gate driver U6. The filter circuit is configured to remove high frequency noise from the input voltage signal VGATE input to the pin OD.

The pin OD of the integrated gate driver U7 receives the filtered signal GATEON.

The transistors Q1 and Q4 field-effect transistors (FETs). A gate of the transistor Q1 and a first terminal of the resistor R21 are connected to the high side gate driver pin DRVH (pin 8) of the integrated gate driver U7 at a node Node18.

A source of the transistor Q1 is connected to a second terminal of the resistor R21, an anode of a Zener diode D3, a drain of the transistor Q4, a first terminal of a capacitor C35, a second terminal of the capacitor C27 and the switching node pin SWN (pin 7) of the integrated gate driver U7 at node Node16.

A gate of the transistor Q4 is connected to the low side gate driver pin DRVL (pin 5) of the integrated gate driver U7 and a first terminal of a resistor R27 at a node Node19. A source of the transistor Q4 and a second terminal of the resistor R27 are connected to ground.

A second terminal of the capacitor C35 is connected to a first terminal of a resistor R29. A second terminal of the resistor R29 is connected to ground.

A drain of the transistor Q1 is connected to a first terminal of a capacitor C36, a cathode of the Zener diode D3 and a cathode of a Zener diode D5 at a node Node20. A second terminal of the capacitor C36 and an anode of the Zener diode D5 are connected to ground. An output terminal 7065 of the second stage 7060 is connected to the node Node20 and outputs the input voltage signal COIL_OUT. The output terminal 7065 serves as the output of the heating engine control circuit 2127.

The capacitor C35 may be a smoothing capacitor and the resistor limits in-rush current. The Zener diode D3 is a blocking diode to stop a voltage in the node Node20 discharging into the capacitor C35. The capacitor C36 is an output capacitor charged by the second stage 7060 (and reduces ripple in COIL_OUT) and the Zener diode D5 is an ESD (electrostatic discharge) protection diode.

When the low side gate drive signal output from the low side gate driver pin DRVL is high, the transistor Q4 is in a low impedance state (ON), thereby connecting the node Node16 to ground and increasing the energy stored in the magnetic field of the inductor L4.

As mentioned above, because the capacitor C27 is connected to the input voltage signal VGATE from the boost converter circuit 7020, the capacitor C27 charges to a voltage equal or substantially equal to the input voltage signal VGATE through the diode D1.

When the low side gate drive signal output from the low side gate driver pin DRVL is low, the transistor Q4 switches to the high impedance state (OFF), and the high side gate driver pin DRVH (pin 8) is connected internally to the bootstrap pin BST within the integrated gate driver U7. As a result, transistor Q1 is in a low impedance state (ON), thereby connecting the switching node SWN to the inductor L4.

In this case, the node Node15 is raised to a bootstrap voltage V(BST)≈V(VGATE)+V(INDUCTOR), which allows the gate-source voltage of the transistor Q1 to be the same or substantially the same as the voltage of the input voltage signal VGATE (e.g., V(VGATE)) regardless (or independent) of the voltage from the inductor L4. As the second stage 7060 is a boost circuit, the bootstrap voltage may also be referred to as a boost voltage.

The switching node SWN (Node 8) is connected to the inductor voltage and the output capacitor C36 is charged, generating the voltage output signal COIL_OUT (the voltage output to the heater 336) that is substantially independent of the voltage output from the first stage 7040.

FIGS. 8A-8B illustrate methods of controlling a heater in a non-combustible aerosol-generating device according to example embodiments.

Many non-combustible devices use a preheat of organic material (e.g., tobacco) prior to use. The preheat is used to elevate the temperature of the material to a point at which the compounds of interest begin to volatize such that the first negative pressure applied by an adult operator contains a suitable volume and composition of aerosol.

In at least some example embodiments, applied energy is used as a basis for controlling the heater during preheat. Using applied energy to control the heater improves the quality and consistency of the first negative pressure applied by the adult operator. By contrast, time and temperature are generally used as a basis for controlling the preheat.

The methods of FIGS. 8A-8B may be implemented at the controller 2105. In one example, the methods of FIGS. 8A-8B may be implemented as part of a device manager Finite State Machine (FSM) software implementation executed at the controller 2105.

As shown in FIG. 8A, the method includes applying a first power based on a first target preheat temperature at S805. An example embodiment of S805 is further illustrated in FIG. 8B.

As shown in FIG. 8B, the controller detects that a capsule is inserted into the aerosol-generating device. In some example embodiments, the controller obtains a signal from an opening closing switch coupled to the door, which is illustrated in FIGS. 1A-1C. In other example embodiments, the aerosol-generating device further includes (or alternatively includes) a capsule detection switch. The capsule detection switch detects whether the capsule is properly inserted (e.g., capsule detection switch gets pushed down/closes when the capsule is properly inserted). Upon the capsule being properly inserted, the controller may generate the signal PWR_EN_VGATE (shown in FIG. 7A) as a logic high level. In addition, the controller may perform a heater continuity check to determine the capsule is inserted and the heater resistance is within the specified range (e.g. ±20%).

After a capsule has been inserted (as detected by the switch) and/or when the aerosol-generating device 10 is turned on (e.g. by operation of the button), the heater 336 may be powered with a low power signal from the heating engine control circuit (˜1 W) for a short duration (˜50 ms) and the resistance may be calculated from the measured voltage and current during this impulse of energy. If the measured resistance falls within the range specified (e.g. a nominal 2100 mΩ±20%) the capsule is considered acceptable and the system may proceed to aerosol-generation.

The low power and short duration is intended to provide a minimum amount of heating to the capsule (to prevent any generation of aerosol).

At S825, the controller obtains operating parameters from the memory. The operating parameters may include values identifying a maximum power level (P_(max)), initial preheat temperature, subsequent preheat temperature and a preheat energy threshold. For example, the operating parameters may be predetermined based on empirical data or adjusted based on obtained measurements from the capsule (e.g., voltage and current). However, example embodiments are not limited thereto. In addition to or alternatively, the operating parameters may include different initial preheat temperatures for subsequent instances for a multi-instances device. For example, the controller may obtain operating parameters for an initial instance and operating parameters for a second subsequent instance.

At S830, the controller may cause the aerosol-generating device to display an “on” state. The controller may cause the aerosol-generating device to generate a visual indicator and/or a haptic feedback to display an “on” state.

At S835, the controller determines whether a preheat has started. In some example embodiments, the controller may start the preheat upon receiving an input from the on-product controls indicating a consumer has a pressed a button to initiate the preheat. In some example embodiments, the button may be separate from a button that powers on the aerosol-generating device and in other example embodiments, the button may be the same button that powers on the aerosol-generating device. In other example embodiments, the preheat may be started based on another input such as sensing an airflow above a threshold level. In other example embodiments, the on-product controls may permit an adult operator to select one or more temperature profiles (each temperature profile associated operating parameters stored in the memory).

If the controller determines that no preheat has started, the method proceeds to S880 where the controller determines whether an off timer has elapsed. If the off timer has not elapsed, the method returns to S830 and if the controller determines the off timer has elapsed, the controller causes the aerosol-generating device to display an “off” state at S885 and power off at S890. The off timer starts when the detected air flow falls below a threshold level. The off timer is used to display the “off” state based on inaction for a period of time such as 15 minutes. However, example embodiments are not limited to 15 minutes. For example, the duration of the off timer may be between about 5 minutes and about 60 minutes or more.

If the controller determines the preheat has started (e.g., detects input from the on-product controls) at S835, the controller obtains the operating parameters associated with the input from the on-product controls from the memory. In an example, where the aerosol-generating instance is not the initial instance for the capsule, the controller may obtain operating parameters associated with the instance number. For example, the memory may store different temperature targets based on the instance number (e.g., different temperature targets for instance numbers, respectively) and different target energy levels to use for preheating based on the instance number.

The initial instance occurs when the controller initiates the preheat algorithm for a first time after detecting a capsule has been removed and one has since been inserted. Additionally, the instance number increments if the instance times out (e.g. after 8 minutes) or if the consumer switches off the device during an instance.

Upon obtaining the operating parameters at S840, at S845 the controller may cause the aerosol-generating device to display an indication that preheat has started via the aerosol indicators.

At S850, the controller ramps up to a maximum available power to the heater (through the VGATE, COIL_Z and COIL_X signals provided to the heating engine control circuit 2127) (e.g., the controller provides a maximum available power of 10 W within 200 ms). In more detail, the controller requests maximum power, but ramps up to the maximum power to reduce an instantaneous load on the power supply. In an example embodiment, the maximum available power is a set value based on the capability of a battery and to minimize overshoot such that the aerosol-forming substrate is not burnt by the heater (i.e., how much energy can be put into the aerosol-forming substrate without burning). The maximum available power may be set based on empirical evidence and may be between 10-15 W. The controller provides the maximum available power until the controller determines that a target initial preheat temperature of the heater (e.g., 320° C.) is approaching, at S855. While 320° C. is used as an example target initial preheat temperature, it should be understood example embodiments are not limited thereto. For example, the target initial preheat temperature may be less than 400° C., such as 350° C. Moreover, the target initial preheat temperature is based on the materials in the aerosol-forming substrate. The controller may determine the temperature of the heater using the measured voltages from the heater voltage measurement circuit (e.g., COIL_VOL) and the compensation voltage measurement circuit and the measured current from the heater current measurement circuit (e.g., COIL_RTN_I). The controller may determine the temperature of the heater 336 in any known manner (e.g., based on the relatively linear relationship between resistance and temperature of the heater 336).

Further, the controller may use the measured current COIL_RTN_I and the measured voltage COIL_RTN to determine the resistance of the heater 336, heater resistance R_(Heater) (e.g., using Ohm's law or other known methods). For example, according to at least some example embodiments, the controller may divide the measured voltage COIL_RTN (or compensated voltage VCOMP) by the measured current COIL_RTN_I to be the heater resistance R_(Heater).

In some example embodiments, the measured voltage COIL_RTN measured at the measurement contacts for the resistance calculation may be used in temperature control.

For example, the controller 2105 may use the following equation to determine (i.e., estimate) the temperature:

R _(Heater) =R ₀[1+α(T−T ₀)]

where α is the temperature coefficient of resistance (TCR) value of the material of the heater, R₀ is a starting resistance and T₀ is a starting temperature, R_(Heater) is the current resistance determination and T is the estimated temperature.

The starting resistance R₀ is stored in the memory 2130 by the controller 2105 during the initial preheat. More specifically, the controller 2105 may measure the starting resistance R₀ when the power applied to the heater 336 has reached a value where a measurement error has a reduced effect on the temperature calculation. For example, the controller 2105 may measure the starting resistance R₀ when the power supplied to the heater 336 is 1 W (where resistance measurement error is approximately less than 1%).

The starting temperature T₀ is the ambient temperature at the time when the controller 2105 measures the starting resistance R₀. The controller 2105 may determine the starting temperature T₀ using an onboard thermistor to measure the starting temperature T₀ or any temperature measurement device.

According to at least one example embodiment, a 10 ms (millisecond) measurement interval may be used for measurements taken from the heater current measurement circuit 21258 and the heater voltage measurement circuit 21252 (since this may be the maximum sample rate). In at least one other example embodiment, however, for a resistance-based heater measurement, a 1 ms measurement interval (the tick rate of the system) may be used.

In other example embodiments, the determining of the heater temperature value may include obtaining, from a look-up table (LUT), based on the determined resistance, a heater temperature value. In some example embodiments, a LUT indexed by the change in resistance relative to a starting resistance may be used.

The LUT may store a plurality of temperature values that correspond, respectively, to a plurality of heater resistances, the obtained heater temperature value may be the temperature value, from among the plurality of temperature values stored in the LUT, that corresponds to the determined resistance.

Additionally, the aerosol-generating device 10 may store (e.g., in the memory 2130) a look-up table (LUT) that stores a plurality of heater resistance values as indexes for a plurality of respectively corresponding heater temperature values also stored in the LUT. Consequently, the controller may estimate a current temperature of the heater 336 by using the previously determined heater resistance R_(Heater) as an index for the LUT to identify (e.g., look-up) a corresponding heater temperature T from among the heater temperatures stored in the LUT.

Once the controller determines the target initial preheat temperature is approaching, the controller begins to reduce the applied power to the heater to an intermediate power level to avoid a temperature overshoot at S855.

A proportional-integral-derivative (PID) controller (shown in FIG. 9 ) applies a proportionate control based on an error signal (i.e., the target temperature minus the current determined temperature) so, as the error signal reduces towards zero, the controller 2105 starts to back off the power being applied (this is largely controlled by a proportional term (P) of the PID controller, but an integral term (I), and a derivative term also contribute).

The P, I and D values balance overshoot, latency and steady state error against one another and control how the PID controller adjusts its output. The P, I and D values may be derived empirically or by simulation.

FIG. 9 illustrates a block diagram illustrating a temperature heating engine control algorithm according to at least some example embodiments.

Referring to FIG. 9 , the temperature heating engine control algorithm 900 uses a PID controller 970 to control an amount of power applied to the heating engine control circuit 2127 so as to achieve a desired temperature. For example, as is discussed in greater detail below, according to at least some example embodiments, the temperature heating engine control algorithm 900 includes obtaining a determined temperature value 974 (e.g., determined as described above); obtaining a target temperature value (e.g., target temperature 976) from the memory 2130; and controlling, by a PID controller (e.g., PID controller 970), a level of power provided to the heater, based on the determined heater temperature value and the target temperature value.

Further, according to at least some example embodiments, the target temperature 976 serves as a setpoint (i.e., a temperature setpoint) in a PID control loop controlled by the PID controller 970.

Consequently, the PID controller 970 continuously corrects a level of a power control signal 972 so as to control a power waveform 930 (i.e., COIL_X and COIL_Z) output by the power level setting operation 944 to the heating engine control circuit 2127 in such a manner that a difference (e.g., a magnitude of the difference) between the target temperature 976 and the determined temperature 974 is reduced or, alternatively, minimized. The difference between the target temperature 976 and the determined temperature 974 may also be viewed as an error value which the PID controller 970 works to reduce or minimize.

For example, according to at least some example embodiments, the power level setting operation 944 outputs the power waveform 930 such that levels of the power waveform 930 are controlled by the power control signal 972. The heating engine control circuit 2127 causes an amount of power provided to the heater 336 by the power supply 1234 to increase or decrease in manner that is proportional to an increase or decrease in a magnitude of the power levels of a power level waveform output to the heating engine control circuit 2127. Consequently, by controlling the power control signal 972, the PID controller 970 controls a level of power provided to the heater 336 (e.g., by the power supply 1234) such that a magnitude of the difference between a target temperature value (e.g., target temperature 976) and a determined temperature value (e.g., determined temperature 974) is reduced, or alternatively, minimized.

According to at least some example embodiments, the PID controller 970 may operate in accordance with known PID control methods. According to at least some example embodiments, the PID controller 970 may generate 2 or more terms from among the proportional term (P), the integral term (I), and the derivative term (D), and the PID controller 970 may use the two or more terms to adjust or correct the power control signal 972 in accordance with known methods. In some example embodiments, the same PID settings for the initial and subsequent preheat phases may be used.

In other example embodiments, different PID settings may be used for each phase (e.g., if the temperature targets used for the initial and subsequent preheats are substantially different).

FIG. 10 shows an example manner in which levels of the power waveform 930 may vary over time as the PID controller 970 continuously corrects the power control signal 972 provided to the power level setting operation 944. FIG. 10 shows an example manner in which levels of the power waveform 930 may vary as temperature thresholds and energy thresholds are reached. The power in FIG. 10 is COIL_VOL*COIL_CUR. In FIG. 10 , the PID loop will start to lower the applied power from a maximum power P_(max) as the temperature approaches the setpoint, which reduces overshoot of the target temperature.

FIG. 10 is discussed in further detail below.

Referring back to FIG. 8A, the controller determines an estimated energy that has been delivered to the heater as part of applying the first power, at S810.

As shown in FIG. 8B and previously discussed, the controller controls power supplied to the heater at S855. At S860, the controller determines whether an estimated energy applied to the heater has reached a preheat energy threshold. More specifically, the controller integrates the power delivered to the heater since starting the preheat to estimate the energy delivered to the heater. In an example embodiment, the controller determines the power (Power=COIL_VOL*COIL_CUR) applied to the heater every millisecond and uses that determined power as part of the integration.

If the controller determines the preheat energy threshold has not been met, the method proceeds to S855 where power is supplied to the heater as part of the preheating process of the heater.

When the controller determines the applied energy reaches the preheat energy threshold (e.g., 75 J), the controller causes the aerosol-generating device to output a preheat complete indication at S865 via the aerosol indicators.

Referring to both FIGS. 8A and 8B, the controller applies a second power to the heater at S815 upon the preheat energy threshold being met. The second power may be less than the first power.

The controller changes the target initial preheat temperature of the heater to a subsequent preheat temperature (e.g., 300° C.) and the controller reduces input power accordingly to the second power using the temperature control algorithm described in FIG. 9 . The subsequent preheat temperature may be based on empirical data and less than the target initial preheat temperature. In some example embodiments, the subsequent preheat temperature may be based on a number of times a negative pressure is applied to the device with the capsule in the device.

While FIG. 8B and FIG. 10 illustrate preheating to a subsequent preheat temperature target, an adult operator may start aerosol-generation after the initial preheat temperature target is reached. More specifically, the controller 2105 may initiate aerosol-generation (i.e., supplying power to the heater such that the heater reaches a temperature sufficient to produce an aerosol) upon detecting a negative pressure being applied by the adult operator and upon the initial preheat temperature target being reached.

The preheat energy threshold may be determined based on empirical data and determined to be sufficient energy to produce a desired/selected amount of aerosol upon a negative pressure above a pressure threshold being applied.

At S875, the adult operator may apply a negative pressure to the aerosol-generating device. In response, the aerosol-generating device heats the pre-aerosol formulation in the capsule to generate an aerosol.

By using applied energy as a factor for controlling the temperature of the heater and/or during of heating, sensory experience and energy efficiency are improved, resulting in conservation of battery power.

FIG. 10 illustrates a timing diagram of the methods illustrated in FIGS. 8A-8B. At T₁, the preheat commences and the controller ramps up power to apply a first power to the heater, which in this example is a maximum power P_(max). At T₂, the controller determines the heater is approaching an initial preheat target temperature Temp1 (due to reduction in error signal in the PID control loop) and begins to reduce the applied power from P_(max) to an intermediate power P_(int) to avoid a temperature overshoot. The reduction to the intermediate power P_(int) includes at least two intervals Int1 and Int2. The controller reduces the power at a faster rate (i.e., larger slope) than during the interval Int2. The interval Int2 has a smaller rate of change to allow the intermediate power Pint to be reached at substantially the same time the controller determines the initial preheat temperature Temp1 has been reached. The PID settings used for the preheat may be the same for both intervals Int1 and Int2 (e.g., P=100, I=0.25 and D=0). The change in power application during intervals Int1 and Int2 is a result of the reduction in temperature error signal.

At T₃, the controller determines the initial preheat temperature Temp1 has been reached. At T₄, the controller determines the applied energy reaches the preheat energy threshold and reduces the power to a second power P₂ to maintain the temperature of the heater at a subsequent preheat temperature Temp2.

The transition from the intermediate power P_(int) to the second power P₂ includes two intervals Int3 and Int4. In the interval Int3, the controller decreases the power at a first slope. In the interval Int4, the controller increases the power at a slope whose magnitude is less than the magnitude of the first slope. The controller starts the interval Int4, when the power is at P_(dip), which is less than the second power P₂.

According to one or more example embodiments, a (non-combustible) aerosol-generating device may determine the validity of an inserted capsule based on a length of time a maximum power is applied to the heater, measured heating characteristics and/or heating characteristic waveforms (also referred to as profiles) for at least a portion of the capsule (e.g., the heater and/or aerosol-forming substrate) and control the aerosol-generating device based on the determined validity of the capsule. The aerosol-generating device may measure and record the heating characteristics and/or heating characteristic waveforms in real-time.

According to one or more example embodiments, an aerosol-generating device may be configured to determine the validity of a capsule during preheating of the capsule, and to enable or disable further preheating and/or aerosol generation based on whether the capsule is a valid capsule.

Among other things, the aerosol-generating device may include a controller and a memory storing computer-readable instructions. The controller may be configured to execute the computer-readable instructions to cause the aerosol-generating device to: apply power to the heater during a preheat interval; record, during at least a portion of the preheat interval, one or more heating characteristic waveforms resulting from application of power to the heater during the preheat interval; and determine whether the capsule is valid based on the one or more heating characteristic waveforms and/or a length of time a maximum power is applied to the heater. The maximum power applied to the heater may be measured directly.

According to one or more example embodiments, one or more heating characteristics and/or characteristic waveforms (e.g., during at least a portion of an initial preheat from an initial (e.g., room) temperature to an initial preheat temperature target) may be correlated to a number of physical variables in the construction of the capsule. These physical variables may include, for example: (i) the composition of the aerosol-forming substrate (e.g., organic plant materials, or the like) in terms of thermal mass, thermal conductivity within the mass of aerosol-forming substrate, thermal contact with the heater, or the like, which change as the aerosol-forming substrate is depleted; (ii) the construction of the heater in terms of surface area, thermal mass, Temperature Coefficient of Resistance (TCR), structural integrity (e.g., partial short circuits caused by individual elements of the heater contacting with one another), or the like; and/or (iii) materials utilized in the body of the capsule (e.g., the thermal mass and conductivity of the materials), such as the shell or housing component of the capsule where the material(s) used for the shell, and its (their) thickness, may have a relatively strong influence on the heating characteristics of the capsule.

These physical variables may be indicative of the validity of the aerosol-forming substrate and/or the construction of the capsule. As a result, deviations from expected heating characteristics (and/or heating characteristic waveforms) may be utilized to determine whether a capsule inserted into the aerosol-generating device is a valid capsule (e.g., whether the capsule is authentic (or counterfeit), whether the capsule meets relatively stringent production standards (is of sufficient quality), whether the aerosol-forming substrate is depleted or substantially depleted, or the like).

As discussed herein, a valid capsule may refer to, for example, an authentic, properly manufactured capsule (e.g., a capsule of appropriate or sufficient quality and within manufacturing tolerances or relatively stringent production standards), a capsule that has not been damaged or tampered with prior to insertion into the aerosol-generating device, a capsule that is not depleted (e.g., entirely depleted), or the like.

The one or more heating characteristic waveforms may include a recorded resistance waveform (also referred to as a characteristic resistance signature), an applied power waveform (also referred to as an applied power signature and/or a recorded temperature waveform (also referred to as a characteristic temperature waveform). The one or more heating characteristic waveforms may be acquired during preheating of the heater to the target preheat temperature. According to one or more example embodiments, an airflow waveform may also be recorded. The airflow waveform may be utilized to compensate (or mask out) disturbances induced in the other waveforms. The time period during which the one or more heating characteristic waveforms are recorded may be referred to as a validity determination period.

According to at least one example embodiment, the controller may determine whether the capsule is valid based on a comparison between the one or more heating characteristic waveforms and a corresponding one or more expected heating characteristic envelopes (also referred to as profiles, signatures or waveforms). As discussed herein, the one or more expected heating characteristic envelopes may be more generally referred to as capsule validation information, capsule verification information or capsule authentication information. Capsule validation information may be stored in memory. In one example, the capsule validation information may be stored in a look-up table (LUT).

The one or more expected heating characteristic envelopes may include one or more of an expected resistance profile envelope, an expected power profile envelope, and/or an expected temperature profile envelope that is expected in response to application of power to the heater in the capsule during preheating. The controller may compare the one or more heating characteristic waveforms recorded during preheating with corresponding ones of the one or more expected heating characteristic envelopes to determine whether a capsule inserted into the aerosol-generating device is valid.

The expected resistance profile envelope may be defined as an upper and lower resistance bound at each 1 ms time step or ‘tick’ of a timer interval (e.g., at least a portion of the preheating interval). The expected power profile envelope may be defined as an upper and lower power bound at each 1 ms time step or ‘tick’ of the timer interval. The expected temperature profile envelope may be defined as an upper and lower temperature bound at each 1 ms time step or ‘tick’ of the timer interval.

The upper and lower bounds for each of the one or more expected heating characteristic envelopes at each 1 ms tick may be set as desired based on, for example, empirical evidence or testing results obtained on the basis of capsules known to be valid.

In one example, a tolerance of about ±5% from nominal may be used as the upper and lower bounds. Example embodiments should not, however, be limited to this example. Rather, in another example, a tighter tolerance (e.g., ±about 1% from nominal) may be used at the start of the waveform, and the tolerance may increase as the waveform progresses. This may reflect the practical consideration that at the start of the waveform the profile may be more well controlled (e.g., being dominated by the heater construction) than at the end of the waveform wherein the profile may be dominated by the more variable influence of tobacco composition, thermal conduction etc.

Example heating characteristic waveforms will be discussed later with regard to FIGS. 13-19 .

Example embodiments will be discussed in more detail below with regard to the devices and electrical systems described earlier (e.g., in FIGS. 1A-10 ). However, example embodiments should not be limited to these examples.

FIGS. 11A and 11B illustrate a flow chart showing a method for controlling an aerosol-generating device according to example embodiments.

For example purposes, the example embodiment shown in FIGS. 11A and 11B will be described with regard to operations performed by the controller 2105 in FIG. 3 . However, example embodiments should not be limited to this example. The method shown in FIGS. 11A and 11B may be described as being performed by an aerosol-generating device including at least one processor and a memory storing computer-executable instructions, wherein the at least one processor is configured to execute the computer-readable instructions to cause the aerosol-generating device to perform operations of one or more example embodiments. Additionally, the processor, memory and example algorithms, encoded as computer program code, may serve as means for providing or causing performance of operations discussed herein.

Referring to FIGS. 11A and 11B, at S820 the controller 2105 detects that the capsule 100 is inserted into the aerosol-generating device 10 in the same or substantially the same manner as discussed above with regard to S820 in FIG. 8B.

At S825, the controller 2105 obtains operating parameters from the memory 2130 in the same or substantially the same manner as discussed above with regard to S825 in FIG. 8B.

At S830, the controller 2105 causes the aerosol-generating device 10 to display an “ON” state in the same or substantially the same manner as discussed above with regard to S830 in FIG. 8B.

At S835, the controller 2105 determines whether preheat of the aerosol-generating device 10 has started in the same or substantially the same manner as discussed above with regard to S835 in FIG. 8B.

If the controller 2105 determines that preheat has not started, then at S880 the controller 2105 determines whether an off timer has lapsed. The off timer is used to display the “OFF” state based on inaction for a period of time such as 15 minutes. However, example embodiments are not limited to 15 minutes. For example, the duration of the off timer may be between about 5 minutes and about 60 minutes or more. In one example, the off timer may start when the capsule 100 is inserted (and the aerosol-generating device 10 switches on).

If the off timer has not lapsed, then the method returns to S830 and continues as discussed herein.

Returning to S880, if the controller 2105 determines the off timer has lapsed, then the controller 2105 causes the aerosol-generating device 10 to display the “OFF” state at S885 and to power off at S890 as discussed above with regard to FIG. 8B.

Returning to S835, if the controller 2105 determines the preheat has started (e.g., detects input from the on-product controls), then at S1140 the controller 2105 obtains the operating parameters associated with the input from the on-product controls from the memory 2130 in the same or substantially the same manner as discussed above with regard to S840 in FIG. 8B. Also at S1140, the controller 2105 initiates a preheat timer at the clock circuit 2128. The preheat timer tracks the current preheat time interval for the capsule 100.

Upon obtaining the operating parameters and initiating the preheat timer at S1140, at S845 the controller 2105 causes the aerosol-generating device 10 to display an indication that preheat has started via the aerosol indicators 2135 in the same or substantially the same manner as discussed above with regard to S845 in FIG. 8B.

At S1156, the controller 2105 initiates the maximum power timer and the preheat monitor timer. The preheat monitor timer is a timer that defines the length of the measurement window used to record samples for the subsequent capsule validity check of the capsule 100. In one example, the measurement window may be about 7 seconds. The maximum power timer tracks the length of time at which the system is at maximum power (e.g., a maximum available power is applied to the heater 336).

Turning to FIG. 11B, at S855 the controller 2105 applies power to (activates) the heater 336. In one example, the controller 2105 causes the heating engine control circuit 2127 to provide a maximum available power (e.g., about 10 W) to the heater 336 (through the VGATE, COIL_Z and COIL_X signals provided to the heating engine control circuit 2127) in the same or substantially the same manner as discussed above with regard to S850 in FIG. 8B.

In one example, the controller 2105 causes the heating engine control circuit 2127 to apply the maximum available power until the controller 2105 determines that the target initial preheat temperature of the heater 336 (e.g., 320° C.) is approaching. The controller 2105 may determine that the target initial preheat temperature of the heater 336 (e.g., 320° C.) is approaching in the same or substantially the same manner as discussed above with regard to FIG. 8B.

Although not shown in FIGS. 11A and 11B, if an adult operator draws on (e.g., applies sufficient negative pressure to) the aerosol-generating device 10 during preheating (e.g., negative pressure sufficient to trigger detection of air flow by the sensor 1248 and activate the aerosol-generating device 10), the controller 2105 may measure the magnitude of the air flow through the aerosol-generating device 10 and compensate for the induced change in the heating characteristics accordingly. The controller 2105 may measure the magnitude of the air flow based on information from the sensor 1248 in any known manner.

The controller 2105 may compensate for the induced change in the heating characteristics by disregarding (or, alternatively, filtering out) the recorded measurements for the duration of the airflow and a period of settling time thereafter. In one example, the period of settling time may be the same or substantially the same as the length of the airflow event. In this example, the affected portion of time would not be included in the validity check for the capsule 100.

In another example, the controller 2105 may utilize a mathematical permutation to correct the waveform cooling effect caused by the airflow.

In another example, the controller 2105 may calculate the estimated cooling effect of the airflow and the power surge/resistance change induced by the cooling effect based on, for example, a state-space model of the system. The estimated changes may then form an array of correction factors that the controller 2105 may subtract/add as necessary (e.g., the power surge would be subtracted, and the resistance decrease added) to correct and/or compensate the heating characteristic waveforms.

By compensating for the induced change, occurrence of false positives resulting from the application of negative pressure during preheating may be reduced and/or prevented.

Referring back to FIG. 11B, at S1160 the controller 2105 records the power applied to the heater 336, and measures and records one or more of a plurality of heating characteristics for the heater 336 at each 1 ms tick (time step) during the measurement window to generate/obtain the one or more heating characteristic waveforms (e.g., recorded resistance waveform, an applied power waveform and/or a recorded temperature waveform) for the heater 336. As also discussed above, the controller 2105 may also record an airflow waveform, which may be used to, for example, compensate (or mask out) disturbances induced in the other waveforms.

In more detail, for example, to generate the recorded resistance waveform, the controller 2105 may measure the resistance of the heater 336 at each 1 ms time step based on a measured voltage across and current through the heater 336 according to the well-known equation R=V/I. The measured current through the heater 336 may be provided by, or determined based on information provided by, the current measurement circuit 21258. The measured voltage across the heater 336 may be provided by, or determined based on information provided by, the voltage measurement circuit 21252. Alternatively, the controller 2105 may compute and/or monitor the resistance of the heater 336 continuously to generate the recorded resistance waveform.

To generate the applied power waveform, the controller 2105 may compute the instantaneous power across the heater 336 at each 1 ms time step based on the measured voltage across and current through the heater 336 according to the well-known equation P=I×V. The measured current and voltage across the heater 336 may be provided in the same or substantially the same manner as discussed above with regard to the resistance measurements. Alternatively, the controller 2105 may compute and/or monitor the applied power to the heater 336 continuously to generate the applied power waveform.

To generate the temperature waveform, the controller 2105 may compute the temperature of the heater 336 at each 1 ms time step in the same or substantially the same manner as discussed above with regard to S855 in FIG. 8B. Alternatively, the controller 2105 may compute and/or monitor the temperature of the heater 336 continuously to generate the recorded temperature waveform.

To generate the airflow waveform, the controller 2105 may record, in memory 2130, a measurement provided by, for example, the sensor 1248 either continuously or at each 1 ms time step.

Example heating characteristic waveforms will be discussed in more detail later.

Still referring to FIG. 11B, at S1162 the controller 2105 determines whether the power (e.g., instantaneous power) P_(APPLIED) currently applied to the heater 336 (e.g., at the next 1 ms time step) is below the maximum available power P_(MAX). In one example, the power applied to the heater 336 may fall below the maximum available power as the temperature of the heater 336 approaches (or reaches) the target initial preheat temperature (e.g., about 320° C.). For example, if the controller 2105 determines that the temperature of the heater 336 is approaching the target initial preheat temperature, then the controller 2105 may begin to reduce the applied power to the heater 336 to an intermediate power level to avoid a temperature overshoot. According to one or more example embodiments, the continued application of the maximum available power to the heater 336 may indicate that the temperature of the heater 336 has not reached the target initial preheat temperature. According to at least one other example embodiment, the controller 2105 may use the heater power target rather than the power P_(APPLIED) in the check performed at S1162.

If the power applied to the heater 336 is not below the maximum available power (the maximum available power is still being applied to the heater 336), then at S1168 the controller 2105 determines whether the preheat monitor timer has lapsed (or, alternatively, reached the maximum preheat measurement window threshold). As mentioned above, an example length of the preheat monitor timer (or value of the maximum preheat measurement window threshold) may be about 7 seconds.

If the preheat monitor timer has not lapsed, then the process returns to S855 and continues as discussed herein.

Returning to S1168, if the controller 2105 determines that the preheat monitor timer has lapsed, then at S1170 the controller 2105 determines whether the capsule 100 is a valid (or authentic) capsule based on the one or more recorded heating characteristic waveforms and one or more corresponding expected heating characteristic envelopes stored in the memory 2130. The controller 2105 may determine whether the capsule is valid based on a comparison between one or more of the recorded characteristic waveforms and the corresponding one or more expected heating characteristic envelopes. An example embodiment of the validity determination at S1170 will be discussed in more detail later with regard to FIG. 12 .

If the controller 2105 determines that the capsule 100 is not a valid capsule at S1170, then at S1176 the controller 2105 terminates application of power to the heater 336. In one example, the controller 2105 may terminate application of power to the heater 336 in the same or substantially the same manner as discussed above with regard to 6550 in FIG. 6B.

At S1180, the controller 2105 then outputs a fault indication via the aerosol indicators 2135. In one example, the fault indication may be in the form of a sound, visual display and/or haptic feedback. For example, the indication may be a blinking red LED, a software message containing an error code that is sent (e.g., via Bluetooth) to a connected “App” on a remote electronic device, any combination thereof, or the like.

Returning to S1170, if the controller 2105 determines that the capsule 100 is valid, then at S1174 the controller 2105 permits the preheat to continue, and aerosol generation is permitted. In this case, in response to application of a negative pressure to the aerosol-generating device by an adult operator, the aerosol-generating device 10 may heat the aerosol-forming substrate in the capsule 100 to generate an aerosol.

Returning to S1162, if the controller 2105 determines that the applied power is less than the maximum available power, then at S1164 the controller 2105 stops the maximum power timer.

At S1166, the controller 2105 then determines whether the value of the maximum power timer is within an acceptable range (e.g., between a minimum and maximum value). In one example, the maximum timer value may be about 5 seconds and the minimum timer value may be about 2.5 seconds.

If the controller 2105 determines that the value of the maximum power timer is within the acceptable range (e.g., greater than or equal to the minimum timer value, but less than or equal to the maximum timer value), then the process proceeds to S1168 and continues as discussed above.

Returning to S1166, if the controller 2105 determines that the value of the maximum power timer is outside of the acceptable range, then the process proceeds to S1176 and continues as discussed above.

Although FIGS. 11A and 11B are discussed above with regard to activation of preheat by an adult operator, example embodiments may be utilized before activation of the preheat by the adult operator (e.g., during a pre-check of validity, authenticity and/or integrity of the capsule 100). In this example, the authentication routine may be run autonomously (e.g., upon inserting of the capsule) before indicating to the adult operator that the capsule 100 is valid and may be preheated.

FIG. 12 is a flow chart illustrating a method for determining whether a capsule is valid (e.g., at S1170 in FIG. 11B) according to example embodiments.

Referring to FIG. 12 , at S1210 the controller 2105 determines whether the one or more recorded heating characteristic waveforms are within the bounds of the corresponding one or more expected heating characteristic envelopes. In one example, the controller 2105 may compare the recorded resistance waveform with the expected resistance profile envelope (defined as an upper and lower resistance bound at each 1 ms tick) to determine whether the recorded resistance value at each 1 ms tick is within the bounds of the expected resistance at the corresponding point in the expected resistance profile envelope; the controller 2105 may compare the applied power waveform with the expected power profile envelope (defined as an upper and lower power bound at each 1 ms tick) to determine whether the recorded power value at each 1 ms tick is within the bounds of the expected power at the corresponding point in the expected power profile envelope; and/or the controller 2105 may compare the recorded temperature waveform with the expected temperature profile envelope (defined as an upper and lower temperature bound at each 1 ms tick) to determine whether the recorded temperature value at each 1 ms tick is within the bounds of the expected temperature at the corresponding point in the expected temperature profile envelope.

According to example embodiments, lengths of any or all of the expected heating characteristic envelopes may be interpolated or decimated as needed to match the length of the recorded heating characteristic waveforms (e.g., to match the length of the measurement window and/or depending on the actual length of the preheating).

Still referring to FIG. 12 , if at least a portion (e.g., one or more data points) of one or more (e.g., any) of the recorded heating characteristic waveforms are outside the bounds of the corresponding expected heating characteristic envelopes, then the controller 2105 determines that the capsule is not valid at S1240.

Returning to S1210, if each of the one or more recorded heating characteristic waveforms are within the bounds of the corresponding expected heating characteristic envelopes, then at S1220 the controller 2105 determines whether any sharp positive or negative gradients are present in one or more of the heating characteristic waveforms.

In at least one example embodiment, the controller 2105 determines whether any sharp positive or negative gradients are present in the recorded resistance waveform by comparing two resistance values separated by a given time period (referred to herein as the gradient threshold time period or measurement window). The length of the time period may be as small as one sample (e.g., about 1 ms), but may also include a plurality of samples. In one example, the time period may be 64 samples (about 64 ms) to ensure that the system may detect lower gradients (albeit still gradients that are beyond what may be expected for a normally operating system). In one example, the maximum permitted rate of change of resistance may be about 3% per 64 ms. However, example embodiments should not be limited to this example. Rather, the maximum permitted rate of change of resistance may be greater than or equal to about 3%. Additionally, for different (e.g., smaller) time periods, the maximum permitted change of resistance may be less than 3% (e.g., about 1% or 2%).

If the percentage change in magnitude (positive or negative) between the two resistance values separated by the time period (percentage change in resistance) exceeds (is greater than) a threshold value (percentage change threshold value), then a sharp gradient is determined to be present in the recorded waveform. The percentage change threshold value may be set to be greater than the resistance change that may be expected due to normal heating or cooling effects (e.g., the percentage threshold value may be a value that is physically impossible). In one example, the percentage change threshold value may be about 3%. However, example embodiments should not be limited to this example.

Still referring to FIG. 12 , if the controller 2105 determines that sharp positive or negative gradients are present in the recorded resistance waveform, then the controller 2105 determines that the capsule is not valid at S1240.

Returning to S1220, if the controller 2105 determines that there are no sharp positive or negative gradients present in the recorded resistance waveform, then the controller 2105 determines that the capsule is valid at S1230.

The example embodiments shown in FIGS. 11A, 11B and 12 are discussed with regard to initiation in response to inserting a capsule into the aerosol-generating device (e.g., at S820). These example embodiments may be utilized in connection with a newly inserted capsule. According to at least some example embodiments, the validation may be omitted for a subsequent preheat (e.g., after a time between operation, such as after power off and power on) since the capsule has already been validated during the initial preheat, and the aerosol-generating device has not detected that the capsule has not been removed and a new capsule inserted. However, example embodiments should not be limited to this example. Rather, example embodiments may also be utilized for re-validating a capsule for subsequent operation by an adult operator (e.g., after power off and power on). In this case, step S820 may be omitted from the process, and the method may be initiated or triggered at, for example, power on.

In at least one example, for re-validation, the tolerance for the waveforms may be increased (e.g., to about ±30%) and the permitted range of the maximum power timer at S1166 may be increased to, for example, between about is and about 5 s. These changes may be sufficient to accommodate a now at least partially depleted capsule, but to still detect a gross error that manifested during operation.

Alternatively, the tolerance and the timer may be de-rated in a more controlled way (e.g., by estimating depletion of the capsule based on the cumulative length of the operation so far, or the number of draws by the adult operator after the capsule has been inserted).

Additionally, for re-validation, the discontinuity checks at S1220 in FIG. 12 may be omitted since these characteristics may be unaffected by the depletion of the capsule.

FIG. 13 is a graph illustrating recorded waveforms for a valid capsule according to example embodiments.

FIG. 14 is an enlarged view of a portion of the recorded waveforms shown in FIG. 13 . The graph in FIG. 14 illustrates the initial rise portion of the waveforms (between 0 and about 3 seconds) in more detail.

Referring to FIGS. 13 and 14 , the recorded waveforms include the characteristic temperature waveform (in Celsius), the characteristic resistance waveform (in mΩ) and the applied power waveform (in mW). As mentioned similarly above, the characteristic temperature waveform illustrates the characteristic temperature rise time and may be mathematically derived from measured resistance values for the heater (e.g., heater 336). The characteristic resistance waveform may be influenced by the heater itself and/or the organic mass in contact with the heater 336.

In this example, for the valid capsule, the resistance of the heater substantially stabilizes once the preheat temperature is reached (e.g., after about 5 s). The stabilizing of the heater resistance may cause an artefact as shown more clearly in FIG. 14 . In one example, the artefact may be a result of wetting effects.

The applied power waveform illustrates the time at maximum power (also referred to as “Time at Max Power” characteristic or interval), which is about 4 s in this example. As shown, the maximum power is about 10 W. At the end of the Time at Max Power interval, a power roll-off occurs in which the power to the heater falls to a steady state (e.g., about 4 W). The power roll-off may be a system characteristic, which may be influenced by the organic mass in contact with the heater, the PID settings, the mass of the heater, etc.

FIG. 15 is a graph illustrating recorded waveforms for a degraded and invalid capsule according to example embodiments.

FIG. 16 is an enlarged view of the waveforms shown in FIG. 15 . The graph in FIG. 16 illustrates the initial rise portion of the waveforms in more detail.

The waveforms shown in FIGS. 15 and 16 are examples associated with a capsule that has been degraded by the depletion of organics through prior operation of the aerosol-generating device, thereby resulting in a change in thermal response. However, similar deviations from the waveforms shown in FIGS. 13 and 14 may be used to detect other types of invalid capsules (e.g., wrong organic matter, incorrect heater mass, etc.).

As shown in FIG. 15 , the ‘Time at Max Power’ interval is reduced from about 4 s to about 2 s relative to the example shown in FIGS. 13 and 14 . Moreover, the power roll-off is sharper than the example shown in FIG. 13 . Additional noise is also present in the applied power indicating that the system may be thermally over responsive (e.g., relatively small power fluctuations cause relatively large temperature changes). The resistance of the heater also stabilizes, and the preheat temperature is reached, in about 2 s, as opposed to about 5 s in the example shown in FIG. 13 .

FIG. 17 is a graph illustrating recorded waveforms for another example valid capsule according to example embodiments. The waveforms shown in FIG. 17 are associated with a valid capsule when a second preheat is used during an airflow (or puff) event.

As shown in FIG. 17 , the airflow event during the initial preheating does not affect the applied power because the maximum available power is already being applied to the heater. This airflow does, however, cool the system, which results in a decrease (e.g., relatively small decrease) in resistance. The subsequent airflow event after the power applied to the heater falls below the maximum available power (e.g., around about 4 s), cools the heater. As a result, the power applied to the heater is increased to maintain the temperature of the heater. This increased power continues after the airflow event ends (e.g., about is later) as the system recovers from lost energy. In one example, the system may compensate for the airflow by ignoring the features for approximately double the length of the airflow event.

In the example shown in FIG. 17 , the Time at Max Power interval is about 2.5 s. This reduction in length of the Time at Max Power interval relative to the example shown in FIG. 13 , in which the Time at Max Power interval is about 4 s, may indicate that the capsule has been heated previously, but not fully depleted, and thus remains a valid capsule.

FIG. 18 is a graph illustrating a recorded waveforms for another invalid capsule according to example embodiments.

FIG. 19 is an enlarged view of the waveforms shown in FIG. 18 . The graph in FIG. 19 illustrates the discontinuity in resistance in more detail.

The waveforms shown in FIGS. 18 and 19 illustrate an example of a sharp negative gradient in a characteristic resistance waveform resulting from a heater fault (e.g., due to an intermittent heater short circuit) within the capsule.

As shown in FIGS. 18 and 19 , the ‘Time at Max Power’ interval is about 4 s and the power roll-off remains substantially the same as for a valid capsule shown in FIG. 13 . In the characteristic resistance waveform, however, the heater fault results in a measured discontinuity or sharp negative gradient (sharp drop) in resistance for a period of time. In at least some cases, this discontinuity may be more likely to occur during the initial phase of heating due to, for example, the thermal shock of the heater.

As discussed similarly above with regard to S1220 in FIG. 12 , the discontinuity or sharp negative gradient may be detected by monitoring for a gradient shift in the characteristic resistance waveform greater than expected from heating or cooling. In one example, a gradient shift of greater than about 3% of a previous resistance value within a single 1 ms sample may indicate that there is a discontinuity in the resistance waveform. In another example, a gradient shift of greater than about 3% of a previous resistance value within a 64 ms interval may indicate that there is a discontinuity in the resistance waveform.

One or more example embodiments provide mechanisms to determine an authenticity and/or integrity (e.g., degradation) of a capsule (e.g., during preheating of the capsule) based on thermal characteristics (e.g., the temperature rise time for the heater as indicated by the current power demand) of the capsule (e.g., during preheating). Determining the authenticity and/or integrity of a capsule may also be referred to as performing an authenticity and/or integrity check. In one example, the authenticity and/or integrity check may indicate whether the capsule is sufficiently well constructed (e.g., whether the organic material is in satisfactory thermal contact with the heater) for aerosol generation.

One or more other example embodiments provide mechanisms for detecting reuse of a capsule based on the thermal characteristics (e.g., the temperature rise time for the heater as indicated by the current power demand) of the capsule (e.g., during preheating). In one example, capsule reuse detection may indicate whether the organic material in the capsule (e.g., the aerosol-generating substrate) has sufficient volatile content for aerosol generation. Insufficient volatile content for aerosol generation may be a result of the capsule having been previously inserted into, and the aerosol-generating substrate subjected to heating by, the aerosol-generating device for any length of time. In one example, the capsule may be determined to have been previously subject to heating by an aerosol-generating device for greater than a threshold time period (e.g., 1 s, 2 s, 5 s, etc.). Accordingly, a reused capsule may refer to a capsule that has been previously inserted into, and subjected to heating by, an aerosol-generating device for any length of time.

In both poor construction (authenticity and/or integrity check) and prior heating (capsule reuse detection), the proportion of energy conducted into the aerosol-generating substrate in a given time is reduced, which may result in the heater reaching a target temperature more quickly than expected. An example of this is illustrated in FIG. 22 , which shows an example comparison of recorded power target waveforms for an authentic and unheated capsule and a reused capsule.

As shown in FIG. 22 , preheating of the authentic and unheated capsule requires maximum power (e.g., about 10 W) for at least about 3 s to approach the temperature target, whereas the reused capsule exhibits a power roll off from the maximum power before 2 s since it is already approaching the temperature target at that time. The temperature target may be the same or substantially the same as that discussed above.

Example embodiments of methods for capsule reuse detection will now be discussed in more detail with regard to FIGS. 20 and 21 . Although will be discussed in the context of capsule reuse detection, it will be understood that the methods shown and described herein may also be utilized to determine authenticity and/or integrity of a capsule in order to detect an inauthentic and/or degraded capsule in the same or substantially the same manner.

For example purposes, the example embodiment shown in FIGS. 20 and 21 will be described with regard to operations performed by the controller 2105 in FIG. 3 . However, example embodiments should not be limited to these examples.

At least with regard to the example embodiments shown in FIGS. 20 and 21 , the applied power P_(APPLIED) may refer to a power target or to a power output.

FIG. 20 is a flow chart illustrating a method for capsule reuse detection according to one or more example embodiments.

As discussed in more detail below, according to at least this example embodiment, the controller 2105 monitors the initial preheat phase in order to determine whether a minimum power delivery profile has been met. Similar to the method described above with regard to FIG. 11B, the method shown in FIG. 20 may be performed during preheating, after the operations shown in FIG. 11A. However, example embodiments should not be limited to this example.

Referring to FIG. 20 , after the controller 2105 initiates the maximum power timer and the preheat monitor timer at S1156 in FIG. 11A, at S850 the controller 2105 ramps up to a maximum available power to the heater 336 (through the VGATE, COIL_Z and COIL_X signals provided to the heating engine control circuit 2127) in the same or substantially the same manner as discussed above with regard to FIG. 11B.

At S1160, in the same or substantially the same manner as discussed above with regard to FIG. 11B, the controller 2105 records the power applied to the heater 336, and measures and records one or more of a plurality of heating characteristics for the heater 336 at each 1 ms tick (time step) during the measurement window.

At S2020, the controller 2105 determines whether the preheat monitor timer has reached a capsule reuse timer detection threshold t_(TH_R). In one example, the capsule reuse timer detection threshold t_(TH_R) may be about 2 s. However, example embodiments should not be limited to this example. Rather, the capsule reuse timer detection threshold t_(TH_R) may between about 2 s and 5 s.

If the preheat monitor timer has not yet reached the capsule reuse timer detection threshold t_(TH_R), then at S2022 the controller 2105 determines whether the power (e.g., instantaneous power) P_(APPLIED) currently applied to the heater 336 (e.g., at the next 1 ms time step) is below a minimum applied power threshold P_(TH_1). In one example, the minimum applied power threshold P_(TH_1) may be set to about 90% of the maximum applied power P_(MAX) (e.g., about 9 W, which is 90% of P_(MAX)=about 10 W). More generally, according to one or more example embodiments, the minimum applied power threshold P_(TH_1) may be set such that (e.g., only) macro movements of the applied power P_(APPLIED) trigger the capsule reuse detection.

If the applied power P_(APPLIED) is below the minimum applied power threshold P_(TH_1), then the controller 2105 determines that an early roll off of the applied power P_(APPLIED) has occurred and that the capsule is a reused capsule.

In response to determining that the capsule is a reused capsule, at S1176 the controller 2105 terminates application of power to the heater 336 in the same or substantially the same manner as discussed above with regard to FIG. 11B.

The controller 2105 then outputs a fault indication via the aerosol indicators 2135 at S1180 in the same or substantially the same manner as discussed above with regard to FIG. 11B. In another example, at S1180 the controller 2105 may control the aerosol generating device to output a ‘Capsule Empty’ indicator via the aerosol indicators 2135.

According to one or more example embodiments, the early roll-off detection at step S2020 allows for flagging of reused (and/or degraded, inauthentic, or other lesser) capsule relatively early in the preheat process.

Returning to S2022, if the controller 2105 determines that the power P_(APPLIED) is greater than or equal to the minimum applied power threshold P_(TH_1), then the process returns to step S855 and continues as discussed herein.

Returning now to S2020, if the preheat monitor timer has reached the capsule reuse timer detection threshold t_(TH_R), then at S2024 the controller 2105 determines whether the power (e.g., instantaneous power) P_(APPLIED) currently applied to the heater 336 (e.g., at the next 1 ms time step) is below a second minimum applied power threshold P_(TH_2). In one example, the second minimum applied power threshold P_(TH_2) may be set to about 98% of the maximum applied power P_(MAX) (e.g., about 9.8 W, which is 98% of P_(MAX)=about 10 W).

If the power P_(APPLIED) is below the second minimum applied power threshold P_(TH_2), then the controller 2105 determines that an early roll off of the applied power P_(APPLIED) has occurred and that the capsule is a reused capsule. The process then proceeds to S1176 and continues as discussed herein.

Returning to step S2024, if the power P_(APPLIED) is greater than or equal to the second minimum applied power threshold P_(TH_2), then at S1174 the controller 2105 permits preheating to continue, and aerosol generation is permitted, in the same or substantially the same manner as discussed above with regard to FIG. 11B.

Although described with regard to the preheat monitor timer, the example embodiment shown in FIG. 20 may utilize a separate timer.

According to one or more example embodiments, the capsule reuse detection function (and/or the authenticity or integrity check function) may be set to ‘Monitor’ mode (also referred to as ‘Diagnostic’ mode) for diagnostic purposes. In one example, the monitor mode may be set via a device manager setting at the controller 2105 (e.g., via a flag). The monitor mode may enable gathering of diagnostic information at least with regard to capsule reuse detection of the aerosol-generating device to improve functionality.

FIG. 21 is a flow chart illustrating a method for capsule reuse detection including monitor mode functionality, according to one or more example embodiments. The method shown in FIG. 21 is similar to the method shown in FIG. 20 , and thus, only differences between the example embodiments will be discussed in detail here.

Referring to FIG. 21 , in this example embodiment, if the power P_(APPLIED) is below the minimum applied power threshold P_(TH_1) at S2022, then at S2026 the controller 2105 sets the power profile failed flag (e.g., POWER PROFILE FAILED FLAG=TRUE) to indicate, for example, that a reused capsule (or, alternatively, an inauthentic capsule) has been detected. The power profile failed flag may be implemented by a flag bit.

At S2028, the controller 2105 then checks whether the aerosol generating device is set to the monitor mode (e.g., the controller 2105 determines whether the DETECTION MODE=MONITOR).

If the aerosol-generating device is not set to the monitor mode, then the process proceeds to S1176 and continues as discussed above with regard to FIG. 20 .

Returning to S2028, if the aerosol generating device is set to the monitor mode, then at S2030 the controller 2105 stores diagnostic information associated with the detected roll off in a memory. In one example, the diagnostic information may include fault conditions, such as waveforms recorded at S1160 at the time the reused capsule is detected. The process then proceeds to S1174 and continues as discussed above with regard to FIG. 20 .

Turning to step S2024 in FIG. 21 , in this example embodiment, if the controller 2105 determines that the power P_(APPLIED) currently applied to the heater 336 (e.g., at the next 1 ms time step) is below above a second minimum applied power threshold P_(TH_2), then the process proceeds to step S2026 and continues as discussed herein.

Although not shown in FIGS. 20 and 21 , according to one or more example embodiments, after detecting that the power P_(APPLIED) is greater than or equal to the second minimum applied power threshold P_(TH_2) at S2024, the controller 2105 may also set a power profile checked flag (POWER PROFILE CHECKED FLAG=TRUE). The controller 2105 may then check the power profile checked flag each time the preheat monitor timer has reached the capsule reuse timer detection threshold t_(TH_R) to determine whether to perform capsule reuse detection. The power profile checked flag may ensure that the controller 2105 only performs the capsule reuse detection during the initial preheating (e.g., prior to 2 s), and not on subsequent preheating (e.g., following a puff where the same or similar logic is used and/or where multi-puff mode is activated) and/or to prevent interpreting normal roll off as early roll off.

One or more example embodiments provide the ability to detect whether a capsule is of degraded quality or has been heated previously, which may reduce the likelihood that adult operators receive a relatively poor experience and/or prevent operation of an aerosol-generating device with unauthorized counterfeit products.

By detecting the degraded quality shortly after start of operation of the aerosol-generating device (e.g., during the initial preheat), the determination may be made early and communicated to the adult operator, while also terminating operation of the aerosol-generating device.

Measurement of the intrinsic physical characteristics of a capsule for detecting whether a capsule is valid, according to one or more example embodiments, may provide a relatively low cost manner in which to determine validity. The additive cost to the aerosol-generating device may also be reduced because the measurement technique employs circuitry already implemented for the purposes of accurate control of the sensory experience of the capsule.

Aerosol-generating devices according to one or more example embodiments include an integrated heater element and utilize precision heater control electronics that enables measurement and monitoring of a characteristic preheating curve in order to determine validity, authenticity, build quality and/or depletion status of the capsule.

One or more example embodiments may also enable detection of unauthorized reuse of a capsule to create a counterfeit capsule.

One or more example embodiments also provide the ability to detect (e.g., via the recorded heating characteristic waveforms and corresponding expected heating characteristic envelopes) unexpected, relatively short duration artefacts within the characteristic preheating curve that, while still within the bounds of the acceptable characteristic envelopes, are indicative of possible build quality issues with the capsule (e.g., the heater). These artefacts may be exposed as the heater experiences thermal shock associated with the rapid rise from room temperature to a temperature to generating aerosol.

Further to the non-limiting embodiments set forth herein, additional details of the substrates, capsules, devices, and methods discussed herein may also be found in U.S. application Ser. No. 16/451,662, filed Jun. 25, 2019, titled “CAPSULES, HEAT-NOT-BURN (HNB) AEROSOL-GENERATING DEVICES, AND METHODS OF GENERATING AN AEROSOL,” Atty. Dkt. No. 24000NV-000522-US; U.S. application Ser. No. 16/252,951, filed Jan. 21, 2019, titled “CAPSULES, HEAT-NOT-BURN (HNB) AEROSOL-GENERATING DEVICES, AND METHODS OF GENERATING AN AEROSOL,” Atty. Dkt. No. 24000NV-000521-US; U.S. application Ser. No. 15/845,501, filed Dec. 18, 2017, titled “VAPORIZING DEVICES AND METHODS FOR DELIVERING A COMPOUND USING THE SAME,” Atty. Dkt. No. 24000DM-000012-US; and U.S. application Ser. No. 15/559,308, filed Sep. 18, 2017, titled “VAPORIZER FOR VAPORIZING AN ACTIVE INGREDIENT,” Atty. Dkt. No. 24000DM-000003-US-NP, the disclosures of each of which are incorporated herein in their entirety by reference.

While a number of example embodiments have been disclosed herein, it should be understood that other variations may be possible. Such variations are not to be regarded as a departure from the spirit and scope of the present disclosure, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. 

What is claimed is:
 1. A non-combustible aerosol-generating device, comprising: a memory storing computer-readable instructions; and a controller configured to execute the computer-readable instructions to cause the non-combustible aerosol-generating device to apply power to a heater to preheat an aerosol-forming substrate, determine whether a preheat monitor timer has exceeded a preheat timer threshold, determine whether the aerosol-forming substrate has been previously heated based on a comparison between a first threshold power level and an applied power to the heater in response to the preheat monitor timer having not exceeded the preheat timer threshold, and determine whether the aerosol-forming substrate has been previously heated based on a comparison between a second threshold power level and the applied power to the heater in response to the preheat monitor timer having exceeded the preheat timer threshold.
 2. The non-combustible aerosol-generating device of claim 1, further comprising: a capsule including the aerosol-forming substrate and the heater.
 3. The non-combustible aerosol-generating device of claim 1, wherein the controller is configured to execute the computer-readable instructions to cause the non-combustible aerosol-generating device to terminate application of power to the heater in response to determining that the aerosol-forming substrate has been previously heated.
 4. The non-combustible aerosol-generating device of claim 3, wherein the controller is configured to execute the computer-readable instructions to cause the non-combustible aerosol-generating device to output a fault indication in response to determining that the aerosol-forming substrate has been previously heated.
 5. The non-combustible aerosol-generating device of claim 1, wherein the controller is configured to execute the computer-readable instructions to cause the non-combustible aerosol-generating device to output a fault indication in response to determining that the aerosol-forming substrate has been previously heated.
 6. The non-combustible aerosol-generating device of claim 1, wherein the controller is configured to execute the computer-readable instructions to cause the non-combustible aerosol-generating device to allow for aerosol generation in response to determining that the aerosol-forming substrate has not been previously heated.
 7. The non-combustible aerosol-generating device of claim 1, wherein the first threshold power level is less than the second threshold power level.
 8. The non-combustible aerosol-generating device of claim 1, wherein the applied power is a maximum power applied to the heater or a power target for the heater.
 9. The non-combustible aerosol-generating device of claim 8, wherein the first threshold power level and the second threshold power level are based on the maximum power or the power target.
 10. A method of operating a non-combustible aerosol-generating device, the method comprising: applying power to a heater to preheat an aerosol-forming substrate; determining whether a preheat monitor timer has exceeded a preheat timer threshold; determining whether the aerosol-forming substrate has been previously heated based on a comparison between a first threshold power level and an applied power to the heater in response to the preheat monitor timer having not exceeded the preheat timer threshold; and determining whether the aerosol-forming substrate has been previously heated based on a comparison between a second threshold power level and the applied power to the heater in response to the preheat monitor timer having exceeded the preheat timer threshold.
 11. A non-transitory computer-readable storage medium storing computer-readable instructions that, when executed by a controller at a non-combustible aerosol-generating device, cause the controller to perform a method of operating the non-combustible aerosol-generating device, the method comprising: applying power to a heater to preheat an aerosol-forming substrate; determining whether a preheat monitor timer has exceeded a preheat timer threshold; determining whether the aerosol-forming substrate has been previously heated based on a comparison between a first threshold power level and an applied power to the heater in response to the preheat monitor timer having not exceeded the preheat timer threshold; and determining whether the aerosol-forming substrate has been previously heated based on a comparison between a second threshold power level and the applied power to the heater in response to the preheat monitor timer having exceeded the preheat timer threshold.
 12. A non-combustible aerosol-generating device, comprising: a memory storing computer-readable instructions; and a controller configured to execute the computer-readable instructions to cause the non-combustible aerosol-generating device to apply power to a heater to preheat an aerosol-forming substrate within a capsule, determine whether a preheat monitor timer has exceeded a preheat timer threshold, determine whether the capsule is at least one of an inauthentic or degraded capsule based on a comparison between a first threshold power level and n applied power to the heater in response to the preheat monitor timer having not exceeded the preheat timer threshold, and determine whether the capsule is at least one of an inauthentic or degraded capsule based on a comparison between a second threshold power level and the applied power to the heater in response to the preheat monitor timer having exceeded the preheat timer threshold.
 13. The non-combustible aerosol-generating device of claim 12, further comprising: the capsule is a removable capsule including the aerosol-forming substrate and the heater.
 14. The non-combustible aerosol-generating device of claim 12, wherein the capsule is a degraded capsule, and degradation of the capsule is a result of prior heating of the aerosol-forming substrate.
 15. The non-combustible aerosol-generating device of claim 12, wherein the controller is configured to execute the computer-readable instructions to cause the non-combustible aerosol-generating device to terminate application of power to the heater in response to determining that the capsule is at least one of an inauthentic or degraded capsule.
 16. The non-combustible aerosol-generating device of claim 15, wherein the controller is configured to execute the computer-readable instructions to cause the non-combustible aerosol-generating device to output a fault indication in response to determining that the capsule is at least one of an inauthentic or degraded capsule.
 17. The non-combustible aerosol-generating device of claim 12, wherein the controller is configured to execute the computer-readable instructions to cause the non-combustible aerosol-generating device to output a fault indication in response to determining that the capsule is at least one of an inauthentic or degraded capsule.
 18. The non-combustible aerosol-generating device of claim 12, wherein the controller is configured to execute the computer-readable instructions to cause the non-combustible aerosol-generating device to allow for aerosol generation in response to determining that the capsule is not at least one of an inauthentic or degraded capsule.
 19. The non-combustible aerosol-generating device of claim 12, wherein the first threshold power level is less than the second threshold power level.
 20. The non-combustible aerosol-generating device of claim 12, wherein the applied power is a maximum power applied to the heater or a power target for the heater.
 21. The non-combustible aerosol-generating device of claim 20, wherein the first threshold power level and the second threshold power level are based on the maximum power or the power target. 